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atel_9050

Title: New outburst of NGC 2617 Authors: V. L. Oknyansky (Sternberg Astronomical Institute, Moscow), N. A. Huseynov (Shamakhy Astrophysical Observatory, Azerbaijan),. Lipunov, E. S. Gorbovskoy, A. S. Kuznetsov, P. V. Balanutza, A. M. Tatarnikov, V. G. Metlov, N. I. Shatsky, A. E. Nadzhip, M. A. Burlak, K. L. Malanchev (Sternberg Astronomical Institute, Moscow),C. M. Gaskell (UCSC) Date: 14 May 2016; 09:41 UT Provenance: Victor Oknyansky ([email protected]) Subjects: Infra-Red, Optical, AGN Description: Referred to by ATel #: 9053, 11703, 16324 Optical and IR photometry show that the activity of NGC 2617 is continuing and that it is undergoing another outburst. We obtained further JK photometry with the 2.5-m telescope of the SAI Caucasus Mountain Observatory on May 11 (see ATel #9015 for details). NGC 2617 is now brighter than it has been since the end of Jan. The light curve for a 5-arcsecond aperture can be seen here. CCD photometry with the 50-cm AZT-5 telescope of the SAI MSU Crimean Station on May 7 and 9 showed that NGC 2617 had a B magnitude of 14.71 in a 10-arcsecond aperture. This is about 0.3 mag. brighter than on April 22. Unfiltered CCD photometry with a 15-arcsecond (8-pixel) aperture by the MASTER Global Robotic Network at May 11 confirms that NGC 2617 continues to be in a bright state and continues to vary. It is brighter than on Apr. 22 by about 0.1 mag. An updated light curve can be seen http://lnfm1.sai.msu.ru/~oknyan/Combine3_NGC_2617.jpg ">here. (B is shown at the top and the unfiltered MASTER relative magnitudes at bottom - see ATel #9015 for details.) This work has been supported in part by M. V. Lomonosov Moscow State University Development Program. We thank the SAI director, A.M. Cherepashchuk, for granting us director's discretionary time.

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atel_9125

Title: SCP16L01: discovery of an unusual transient in MOO-J1142 Authors: Kyle Boone (UC Berkeley), Greg Aldering (LBNL), Rahman Amanullah (Stockholm), Kyle Barbary (LBNL), Hans Boehringer (MPI), Mark Brodwin (Missouri - Kansas City), Carlos Cunha (Stanford), Susana E. Deustua (STSCI), Sam Dixon (UC Berkeley), Peter Eisenhardt (JPL), Rene Fassbender (INAF, OA Roma), Andrew S. Fruchter (STSCI), Michael Gladders (Chicago), Anthony H. Gonzalez (Florida), Ariel Goobar (Stockholm), Brian Hayden (LBNL), Hendrik Hildebrandt (Bonn, Argelander), Matt Hilton (KwaZulu-Natal), Henk Hoekstra (Leiden), Isobel Hook (Lancaster), Xiaosheng Huang (UC Berkeley), Dragan Huterer (Michigan), Myungkook J. Jee (UC Davis), Alex G. Kim (LBNL), Marek Kowalski (Humboldt), Chris Lidman (AAO), Eric Linder (LBNL), Kyle Luther (UC Berkeley), Joshua Meyers (Stanford), Adam Muzzin (Cambridge), Jakob Nordin (Humboldt), Reynald Pain (LPNHE), Saul Perlmutter (UC Berkeley), Johan Richard (CRAL), Piero Rosati (Ferrara), Eduardo Rozo (Stanford), David Rubin (STSCI), Eli S. Rykoff (Stanford), Joana S. Santos (OA Arcetri), Clare M. Saunders (UC Berkeley), Caroline Sofiatti (UC Berkeley), Anthony L. Spadafora (LBNL), Spencer Adam Stanford (UC Davis), Daniel Stern (JPL), Nao Suzuki (IPMU), Tracy Webb (McGill), Risa H. Wechsler (Stanford), Steven C. Williams (Lancaster), Jon Willis (Victoria), Gillian Wilson (UC Riverside), Michael Yen (UC Berkeley) Date: 8 Jun 2016; 02:13 UT Provenance: Kyle Boone ([email protected]) Subjects: Infra-Red, Optical, Supernovae, Transient Description: We report the discovery of an unusual transient found while monitoring the galaxy cluster MOO-J1142 (z = 1.19) for type Ia supernovae. This transient (named SCP16L01) was discovered with cadenced observations from the Hubble Space Telescope (HST) using the Wide Field Camera 3 (WFC3) instrument as part of the See Change program (HST GO: 13677, 14327; PI: Perlmutter). The transient was discovered on March 10th, 2016 with imaging in the F814W, F105W and F140W filters, with a brightness of 25.47 +/- 0.09 mag AB in the F105W filter. Additional imaging was taken on both April 14th, 2016 and May 15th, 2016. The transient declined rapidly in the F814W (e-folding time of 21 observer days), while simultaneously brightening by a factor of 1.7 in F140W over the 67 observer days between the first and last observations. The AB magnitudes in each of the filters measured using forward modeling photometry are shown in the following table: MJD | F814W | F105W | F140W ---|---|---|--- 57457.7 | 25.18 +/- 0.19 | 25.47 +/- 0.09 | 26.01 +/- 0.13 57492.5 | 26.79 +/- 0.87 | 25.93 +/- 0.12 | 25.74 +/- 0.09 57523.5 | < 27.04 (1 sigma limit) | 26.20 +/- 0.16 | 25.43 +/- 0.08 A machine readable table, cutouts, and plots of the lightcurve can be found at http://supernova.lbl.gov/seechange/SCP16L01/. There is no host detected in the reference images, with 3-sigma limiting magnitudes of 26.5, 27.7 and 27.7 for the F814W, F105W and F140W filters respectively. The redshift of SCP16L01 is not known, and we do not know where it is relative to the cluster. The transient is 0.6 arcminutes from the core of the cluster. The J2000 coordinates for SCP16L01 are 11:42:44.88 +15:27:51.72. The See Change collaboration has no cadenced visits remaining on this field. Additional external observations are encouraged, but they will be very challenging. Additional data for SCP16L01

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atel_9210

Title: Spectral classification of AT2016cyt as a pre-maximum type Ia supernova Authors: A. S. Piascik, I. A. Steele (Liverpool JMU) Date: 5 Jul 2016; 10:23 UT Provenance: Iain Steele ([email protected]) Subjects: Optical, Supernovae, Transient Description: We conducted a spectroscopic observation of transient AT2016cyt at 2016-07-05T04:04:02 UT. This transient was detected by the Puckett Observatory Sky Survey (POSS, T. Puckett, R. Gagliano, E. Weinberg, R. Post, J. Newton) on 2016-07-02T09:21:40 UT at position RA = 21:09:35.83, DEC = 15:07:31.80 and reported via TNS, https://wis-tns.weizmann.ac.il/object/2016cyt A spectrum was obtained in the visible, 400-800nm, with resolution R~350, using the SPRAT spectrograph on the Liverpool Telescope located at Roque de los Muchachos. Classification using SNID (Blondin and Tonry 2007, ApJ, 666, 1024) indicates it is a type Ia supernova. We find a close match with SN2006lf at -6 days with a SNID estimated redshift of z=0.030. The transient is 0.111 arcmin from galaxy NGC 7033, redshift z=0.030374 (source NED). The ejecta velocity estimated from the Si II 635.3nm absorption feature is 11,800 km/s Liverpool Telescope

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atel_9270

Title: ASASSN-16hr: Discovery of A Probable Supernova in 2MASX J22253147+3859010 Authors: J. Brimacombe (Coral Towers Observatory), J. S. Brown, T. W.-S. Holoien, K. Z. Stanek, C. S. Kochanek, J. Shields, D. Godoy-Rivera, U. Basu (Ohio State), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), Subo Dong, S. Bose, Ping Chen (KIAA-PKU), S. Kiyota (Variable Star Observers League in Japan), B. Nicholls (Mt. Vernon Obs., New Zealand), R. S. Post (Post Astronomy), G. Stone (Sierra Remote Observatories) Date: 26 Jul 2016; 19:37 UT Provenance: Jonathan Brown ([email protected]) Subjects: Optical, Supernovae, Transient Description: Referred to by ATel #: 9273 During the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN or "Assassin"), using data from the quadruple 14-cm "Brutus" telescope in Haleakala, Hawaii, we discovered a new transient source, most likely a supernova, in the galaxy 2MASX J22253147+3859010. ASASSN-16hr (AT 2016eja) was discovered in images obtained on UT 2016-07-26.42 at V~16.8 mag. We do not detect (V>17.0) the object in images taken on UT 2016-07-22.44 and before. An image obtained on 2016-07-26 by J. Brimacombe confirms the discovery of the transient. This figure shows the archival SDSS g-band image of the host (left) and the J. Brimacombe confirmation image (right). The red circle has a radius of 5" and is centered on the position of the transient in the J. Brimacombe image. The position of ASASSN-16hr is approximately 1.4" North and 2.5" East from the center of the galaxy 2MASX J22253147+3859010 (no redshift information available from NED). Properties of the new source and photometry are summarized in the tables below: Object RA (J2000) DEC (J2000) Disc. UT Date Disc. V mag Approx. Abs. Mag Offset from Host (") ASASSN-16hr 22:25:31.759 +38:59:03.50 2016-07-26.42 16.8 N/A 2.87 Obs. UT Date V mag 2016-07-22.44 >17.0 2016-07-26.42 16.8 Follow-up observations are encouraged. While we are participating in the TNS system to minimize potential confusion, ASAS-SN will continue using ASASSN-16xx transient names as our primary nomenclature (including supernovae, but also other classes of transients), and we encourage others to do the same. We prefer merging the names as ASASSN-16xx (AT2016xyz) to preserve, rather than anonymize, the origin of the transient. We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported by NSF grant AST-1515927, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, the Mt. Cuba Astronomical Foundation, George Skestos, and the Robert Martin Ayers Sciences Fund. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.

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atel_9390

Title: Sudden optical brightening of M31N 2016-04a Authors: Hiroyuki Maehara (Okayama Astrophysical Observatory, NAOJ, NINS), Seiichiro Kiyota (VSOLJ) Date: 21 Aug 2016; 00:43 UT Provenance: Hiroyuki Maehara ([email protected]) Subjects: Optical, Cataclysmic Variable, Nova, Variables Description: Referred to by ATel #: 9394 We report photometric observations of the sudden brightening of the nova M31N 2016-04a = MASTER OT J004528.12+414117.6 (ATel #8950, #9116). The current brightening was discovered by Koichi Nishiyama and Fujio Kabashima on 2016-08-16.8 at mag 18.1 (TCP J00452804+4141168). According to our photometry, this object was observed at roughly constant brightness (~20.2 mag) from 2016-07-16 to 2016-08-06 and then, the object brightened to 19.8 mag on 2016-08-09, 19.2 mag on 2016-08-10, and 18.7 mag on 2016-08-11. The most recent data show that the object brightened by 2 mag. Our photometric observations performed with the 61cm telescope at Sierra Remote Observatory (iTelescope.net T-24) and the MITSuME 50cm telescope (Kotani et al. 2005, Il Nuovo Cimento C, 58, 755) at Okayama Astrophysical Observatory are summarized as below. Date-Obs. Magnitude Filter Telescope 2016-07-06.760 >19.5 g 50cm@OAO 2016-07-10.763 >19.5 g 50cm@OAO 2016-07-17.466 20.19 L* 61cm@SRO 2016-07-26.463 20.35 L 61cm@SRO 2016-07-31.762 >19.5 g 50cm@OAO 2016-08-06.472 20.22 L 61cm@SRO 2016-08-07.728 >19.5 g 50cm@OAO 2016-08-08.719 >19.5 g 50cm@OAO 2016-08-09.486 19.78 L 61cm@SRO 2016-08-10.380 19.16 L 61cm@SRO 2016-08-10.645 19.3 g 50cm@OAO 2016-08-11.667 18.7 g 50cm@OAO 2016-08-12.634 18.8 g 50cm@OAO 2016-08-14.458 18.49 L 61cm@SRO 2016-08-17.489 18.24 L 61cm@SRO 2016-08-18.473 18.13 L 61cm@SRO *) bandpass: 400-700 nm The flare-like brightening (Δm ~ 2 mag) of this object is similar to that of V723 Cas (e.g., Munari et al. 1996, A&A, 315, 166) and V5558 Sgr (e.g., Tanaka et al. 2011, PASJ, 63, 911). Follow-up observations are encouraged.

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atel_9475

Title: Radio Non-Detection of ASASSN-16jt/SN 2016cvk Authors: S. D. Ryder (AAO), E. C. Kool (Macquarie University/AAO), C. J. Stockdale (Marquette), R. Kotak (QUB), C. Romero-Canizales (UDP, MAS), G. Anderson (Curtin, ICRAR) Date: 9 Sep 2016; 06:12 UT Provenance: Stuart Ryder ([email protected]) Subjects: Radio, Supernovae, Transient Description: The apparently SN 2009ip-like transient ASASSN-16jt coincident with the Type IIn-pec SN 2016cvk (ATel #9439, #9445; http://wis-tns.weizmann.ac.il/object/2016cvk ) in the galaxy ESO 344-G021 has been observed with the Australia Telescope Compact Array (ATCA) at 5.5 and 9 GHz on 2016 Sep 4.6 UT. No radio emission was detected at the reported location, to a 3-sigma upper limit of 68 microJy/beam (5.5 GHz) and 75 microJy/beam (9.0 GHz). Adopting the host galaxy luminosity distance of 41.3 Mpc from NED, this implies an upper limit on the luminosity at 9 GHz of 1.4E26 erg/s/Hz. For comparison SN 2009ip reached a peak 9 GHz luminosity of 5E25 erg/s/Hz at a comparable age (Margutti et al. 2014, ApJ, 780:21). We would like to extend our thanks to the ATCA staff, particularly Phil Edwards for enabling these observations. The Australia Telescope Compact Array is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

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atel_9550

Title: Photometric Follow-Up of A Likely Galactic Nova ASASSN-16kt: Almost Naked Eye Authors: Ping Chen, Subo Dong, S. Bose (KIAA-PKU), K. Z. Stanek, C. S. Kochanek, J. S. Brown, T. W.-S. Holoien, J. Shields (OSU), B. J. Shappee (Hubble Fellow, Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), D. Bersier (LJMU), L. Chomiuk, J. Strader (MSU), J. Brimacombe (Coral Towers Observatory) Date: 26 Sep 2016; 08:53 UT Provenance: Subo Dong ([email protected]) Subjects: Optical, Nova Description: Referred to by ATel #: 9564, 9587, 9594, 9644, 10749 We obtained follow-up photometric observations of ASASSN-16kt (ATel #9538 & ATel #9539) with LCOGT 1m telescope at Sutherland, South Africa (SAAO). We performed aperture photometry on the images using the IRAF apphot package and calibrated the results using the AAVSO Photometric All-Sky Survey (APASS; Henden et al. 2015). JD Filter Mag Err 2457656.2413 B 6.62 0.06 2457657.2292 B 6.86 0.06 2457656.2434 V 6.43 0.05 2457657.2295 V 6.33 0.06 2457656.2457 g 6.61 0.06 2457657.2299 g 6.76 0.08 2457656.2320 i 6.41 0.04 We thank LCOGT and its staff for their continued support of ASAS-SN. ASAS-SN is supported by NSF grant AST-1515927, the Center for Cosmology and AstroParticle Physics (CCAPP) at OSU, and the Mt. Cuba Astronomical Foundation. For more information about the ASAS-SN project, see the ASAS-SN Homepage and the list of all ASAS-SN transients.

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atel_9675

Title: NIR Brightening of the Blazar OJ287 Authors: L. Carrasco, J. Miramon, A. Porras, E. Recillas, V. Chavushyan, D. Y. Mayya (INAOE, Mexico) Date: 27 Oct 2016; 05:09 UT Provenance: LUIS CARRASCO ([email protected]) Subjects: Radio, Infra-Red, Optical, Gamma Ray, AGN, Blazar, Transient Description: Referred to by ATel #: 9709 We have observed a recent NIR flare of the intermediate redshift Blazar OJ287 (z=0.3). On October 26th, 2016, we determined the flux in the H band to be 11.009 +/- 0.02. That is 1 magnitude brighter than the flux determined for this object by our team on JD 2457497. Recent activity of this object had been reported previously in Atel #9629 and #9650. Observations were carried out with the 2.1m telescope of the Guillermo Haro Observatory operated by the National Institute for Astrophysics, Optics and Electronics (Mexico), equipped with the instrument CANICA a NIR camera. We encourage further multi wavelength coverage.

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atel_9780

Title: Detection of the 4th caustic crossing in the Gaia16aye binary microlensing system Authors: I. Khamitov (TUG, Antalya; KFU, Kazan), I. Bikmaev (KFU, AST, Kazan), R. Burenin (IKI, Moscow), S. Grebenev (IKI), M. Tanriver (Erciyes Univ.), A. Avci (Erciyes Univ.), S. Kaynar (TUG), D. Gumus (Ankara Univ.), M. Kocak (TUG), T. Özisik (TUG), M. Dindar (TUG), H. Esenoglu (TUG; Istanbul Univ.), H. Kirbiyik (TUG), O. Okuyan (TUG), T. Saygac (Istanbul Univ.), A. Semena (IKI), A. Tkachenko (IKI), E. Irtuganov (KFU, AST), S. Melnikov (KFU, AST), M. Pavlinsky (IKI), N. Sakhibullin (KFU, AST), R. Sunyaev (IKI) Date: 22 Nov 2016; 08:52 UT Provenance: Sergei Grebenev ([email protected]) Subjects: Optical, Binary, Microlensing Event Description: Following the brightening recently detected in the direction of the Gaia16aye binary microlensing system (ATel #9753) and the subsequent prediction for it of the close caustic crossing (ATel #9770) we organized regular observations of the system with the RTT-150 and T-100 telescopes (Antalya, Turkey) and detected the caustic crossing on Nov. 21, 2016, at 17:54 UTC (JD 2457714.246). The preliminary light curve of this spectacular event can be found here. It shows data from three last nights of our observations, all colors reduced to the V-filter. The brightness reached V=13.37 in the peak. The peak profile was approximated by a parabola, the time of its maximum was taken as the moment of the caustic crossing. Gaia16aye is the first binary microlensing event ever discovered towards the Galactic Plane. The observed one was the 4th and last caustic crossing in the system, the previous ones were reported in Atel #9376, #9507. The RTT-150 telescope will continue to observe this unique object. Ligth curve of Gaia16aye in the V-filter near the moment of caustic crossing

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atel_9840

Title: AGILE detection of a new episode of enhanced gamma-ray emission from the FSRQ CTA102 Authors: F. Verrecchia (ASDC and INAF/OAR), P. Munar-Adrover (INAF/IAPS), C. Pittori, F. Lucarelli (ASDC and INAF/OAR), G. Minervini, G. Piano (INAF/IAPS), A. Bulgarelli (INAF/IASF-Bo), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), I. Donnarumma (INAF/IAPS), V. Fioretti, A. Zoli (INAF/IASF-Bo), S. Vercellone (INAF/OA-Brera), E. Striani (CIFS and INAF/IAPS), M. Cardillo (INAF/OA-Arcetri and INAF/IAPS), F. Gianotti, M. Trifoglio (INAF/IASF-Bo), A. Giuliani, S. Mereghetti, P. Caraveo, F. Perotti (INAF/IASF-Mi), A. Chen (Wits University), A. Argan, E. Costa, E. Del Monte, Y. Evangelista, M. Feroci, F. Lazzarotto, I. Lapshov, L. Pacciani, P. Soffitta, S. Sabatini, V. Vittorini (INAF/IAPS), G. Pucella, M. Rapisarda (ENEA-Frascati), G. Di Cocco, F. Fuschino, M. Galli, C. Labanti, M. Marisaldi (INAF/IASF-Bo), A. Pellizzoni, M. Pilia, A. Trois (INAF/OA-Cagliari), G. Barbiellini, E. Vallazza (INFN Trieste), F. Longo (Univ. Trieste and INFN Trieste), A. Morselli, P. Picozza (INFN and Univ. Roma Tor Vergata), M. Prest (Univ. dell'Insubria), P. Lipari, D. Zanello (INFN and Univ. Roma Sapienza), P. W. Cattaneo, A. Rappoldi (INFN Pavia), S. Colafrancesco (INAF/OAR and Wits University), N. Parmiggiani (University of Modena and Reggio Emilia), A. Ferrari (Univ. Torino and CIFS), F. Paoletti (Princeton Plasma Physics Laboratory), A. Antonelli (ASDC and INAF/OAR), P. Giommi (ASDC), L. Salotti, G. Valentini, and F. D'Amico (ASI) Date: 9 Dec 2016; 18:19 UT Provenance: Francesco Verrecchia ([email protected]) Subjects: Gamma Ray, >GeV, AGN, Blazar, Transient Description: Referred to by ATel #: 9841, 9868, 9869, 9901, 9911, 9924, 10292 AGILE is detecting a new episode of increased gamma-ray emission above 100 MeV from a position consistent with the flat spectrum radio quasar CTA 102 (also known as 4C +11.69, PKS 2230+11, 5BZQ J2232+1143 and as gamma-ray source as 3EG J2232+1147, 3FGL J2232.5+114), recently reported in flaring activity by AGILE on November 24 and 11, 2016 (ATel #9788, #9743), and in optical/NIR extraordinary outburst (ATel #9821, #9808 and #9801). Integrating from 2016-12-07 12:00 UT to 2016-12-09 12:00 UT, a preliminary maximum likelihood analysis yields a detection at 8 sigma at a flux F(E>100 MeV)=(5.6 +/- 1.2) x 10^-6 ph cm^-2 s^-1, while on the integration from 2016-12-05 08:00 UT to 2016-12-07 UT 08:00, we detected a flux F(E > 100 MeV)=(2.7+/-0.8)x 10^-6 ph cm^-2 s^-1. The current flux, the maximum ever measured by AGILE, is almost at the same level of ATel #9788 but after a fast flux variation. This measurement was obtained with AGILE observing a large portion of the sky in spinning mode. Multifrequency observations of CTA 102 are strongly encouraged.

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atel_9925

Title: Spectroscopic Classification of SN 2016jft as a Young Type II Supernova Authors: Danfeng Xiang, Liming Rui, Xiaofeng Wang (Tsinghua University), Jujia Zhang, Xiaoguang Yu (YNAO), Qian Yang, Xuebin Wu (PKU), Feng Xiao, Zhou Fan, Tianmeng Zhang (NAOC) Date: 2 Jan 2017; 14:28 UT Provenance: Xiaofeng Wang ([email protected]) Subjects: Optical, Supernovae, Transient Description: We obtained optical spectra (range 340-900 nm) of SN 2016jft,discovered by Giancarlo Cortini, on UT Dec.31.74 2016 with the 2.16 m telescope at Xinglong Observatory of NAOC and UT Jan.01.74 2017 with the Lijiang 2.4 m telescope of YNAO, respectively. The two specta are consistent with those of a type II supernova at its very young stage, showing a very blue continuum and a broad P-Cygni line profile of Ha. After correcting for a redshift of 0.0174 for its host galaxy UGC 05198, an expansion velocity of about 9900 km/s can be derived from the absorption minimum of Ha line.

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atel_10110

Title: Radio detections of the brightening black hole candidate Swift J1753.5-0127 made with the Arcminute Microkelvin Imager Large Array Authors: J. Bright, T. Staley, R. Fender, S. Motta, (Uni. Oxford), T. Cantwell (Uni. Manchester) Date: 22 Feb 2017; 15:14 UT Provenance: Sara Elisa Motta ([email protected]) Subjects: Radio, X-ray, Binary, Black Hole, Transient Description: Referred to by ATel #: 10114, 10118, 10288, 10325, 10562, 10664, 16262 We report the first new radio detections of the re-brightening black hole X-ray binary candidate Swift J1753.5-0127, obtained on 15 February and 19 February 2017 with the Arcminute Microkelvin Imager Large Array (AMI-LA) interferometer. The unusual low mass X-ray binary source Swift J1753.5-0127 faded to optical, X-ray and radio quiescence in 2016 (ATels #9708, #9739, #9765, #9735) after an outburst phase lasted ~11 years. Recent monitoring with the Faulkes Telescope North (ATel #10075) revealed a 4 magnitude brightening in the V-band (MJD 57797.6) with the source appearing to remain at this new value in follow-up observations (ATel #10097). The new V-band magnitude is comparable to the pre-fading value. Swift XRT ToO observations of the source (ATels #10081, #10097) also show an increase in activity, with an XRT count rate of 0.83 c/s (~300 times the previous XRT upper limit, ATel #9735). We observed this source with the AMI-LA interferometer on 15 February 2017 (MJD 57799.2) and 19 February 2017 (MJD 57803.3) with 4-hour exposure times. We detect a point source at the location of Swift J1753.5-0127 and report flux density measurements of 300 ± 80 μJy on 15 February 2017 and 320 ± 50 μJy on 19 February 2017, both at a central frequency of 15.5 GHz. Swift J1753.5-0127 was extensively monitored by the AMI-LA between January 2013 and July 2015 (Rushton et. al., MNRAS, 2016) who reported a time averaged hard-state flux of 300 μJy followed by a soft-state transition below the array detection limit of 150 μJy per beam. Additionally, the Karl G. Jansky Very Large Array provided an upper limit of 7.5 μJy per beam at 9.0 and 10.65 GHz on 7 November 2016 (MJD 57699.9, ATel #9765). When combined with our recent detections, this indicates an increase in radio flux density of at least a factor ~40 over the last 3.5 months. We plan on continued monitoring of the source with the AMI-LA and would like to thank the Mullard Radio Astronomy Observatory for scheduling these observations.

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atel_10170

Title: Significant increase in the optical brightness of V2492 Cyg Authors: Sunay Ibryamov (Department of Theoretical and Applied Physics, Faculty of Natural Sciences, University of Shumen, Bulgaria), Evgeni Semkov (Institute of Astronomy and NAO, Sofia, Bulgaria) Date: 14 Mar 2017; 17:11 UT Provenance: E. Semkov ([email protected]) Subjects: Optical, Variables, Young Stellar Object, Pre-Main-Sequence Star Description: Referred to by ATel #: 10183, 10259 We observed a recent increase in the optical brightness of the young eruptive star V2492 Cyg using the 2-m and the 50/70-cm Schmidt telescopes administered by National Astronomical Observatory Rozhen in Bulgaria. The current brightness of the object significantly exceeds the registered maximal magnitudes after 2010. V2492 Cyg is located in the Pelican Nebula and its variability and first outburst in 2010 was reported by Itagaki and Yamaoka (CBET #2426), Munari et al. (CBET #2428), Covey et al. (2011, AJ, 141, 40). The nature of the outbursts occurred in V2492 Cyg is still controversial. The object shows consecutive increases and dips in brightness within last seven years. According to Hillenbrand et al. (2013, AJ, 145, 59) both accretion- and extinction-driven mechanisms are responsible for the source variability. The measured BVRI magnitudes of V2492 Cyg during 2016 November - 2017 March, are summarized in the Table below. The table contains date and Julian date of observations, BVRI magnitudes of the object, and telescope used. Typical errors of the reported magnitudes are 0.01-0.02 mag for the I- and R-band data, and 0.01-0.03 mag for the V- and B-band data. Date (DD.MM.YYYY) J.D. B V R I Telescope 05.11.2016 2457698.260 16.31 14.63 13.49 12.21 Schmidt 21.11.2016 2457714.222 15.97 14.25 13.21 11.89 2-m 22.11.2016 2457715.204 15.85 14.27 13.16 11.87 2-m 23.11.2016 2457716.215 16.19 14.44 13.38 11.97 2-m 02.01.2017 2457756.202 15.62 13.96 12.83 11.54 Schmidt 17.02.2017 2457801.603 15.28 13.67 12.57 11.40 Schmidt 05.03.2017 2457817.549 15.11 13.52 12.51 11.37 Schmidt

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atel_10260

Title: The discovery of DLT17ar/AT 2017cyy with PROMPT Authors: L. Tartaglia (TTU, UC Davis), D. Sand, S. Wyatt (TTU), S. Valenti, K. A. Bostroem (UC Davis), D. E. Reichart, J. B. Haislip, V. Kouprianov (UNC) Date: 12 Apr 2017; 18:22 UT Provenance: Leonardo Tartaglia ([email protected]) Subjects: Optical, Supernovae, Transient Description: We report the discovery of DLT17ar/AT 20cyy. The object was discovered on 2017-04-11.18 UT at R~18.68 mag, during the ongoing D<40 Mpc (DLT40) one day cadence supernova search, using data from the PROMPT 5 0.41m telescope located at CTIO. A confirmation image was obtained with the same instrument on 2017-04-12.08 UT, where the transient was detected at R~17.59 mag. DLT17ar/AT 2017cyy is located at RA: 09:36:36.29 Dec: -63:56:54.5, (+23.72''E, -14.50'' N offset from the center of the host galaxy ESO091-015). We do not detect the transient (R>19.9 mag) on 2017-04-10.04 UT or in prior imaging of the field. All images were taken in a 'Clear' filter which was calibrated to an approximate R-band magnitude using the USNO-B1 catalog. Further observations are encouraged.

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atel_10325

Title: The optical flux of Swift J1753.5-0127 strikes back Authors: Federico Bernardini, Guobao Zhang, David M. Russell, Joseph D. Gelfand, Ahlam Al Qasim, Aisha AlMannaei (NYU Abu Dhabi), Fraser Lewis (Faulkes Telescope Project & Astrophysics Research Institute, LJMU), A. W. Shaw (U. Alberta), J. A. Tomsick (SSL/UCB), R. M. Plotkin (ICRAR-Curtin) Date: 28 Apr 2017; 05:38 UT Provenance: Federico Bernardini ([email protected]) Subjects: Optical, Ultra-Violet, X-ray, Binary, Black Hole, Transient Description: Referred to by ATel #: 10562, 10664, 16262 We report on a second re-brightening at optical wavelengths of the transient black hole candidate Swift J1753.5-0127 (hereafter J1753). J1753 was in outburst for 11 years from May 2005 until November 2016 when it was first observed to fade at optical wavelengths (ATel #9708, #9739). Soon after that, it reached the lowest recorded magnitude, V = 21.25 (ATel #9741), which is very close to the quiescent V-band upper limit (V > 21 mag; Cadolle Bel et al. 2007, ApJ, 659, 549), and it was no longer detected at radio and X-ray wavelengths (ATel #9735, #9765). Just two months later, on 30th January 2017, it was found back in outburst (V = 18.37 mag) after becoming once again visible from the ground (ATel #10075). Radio, UV and X-ray follow-up observations confirmed the renewed activity (ATel #10081, #10097, #10110, #10114). Then, a second drop at optical/UV/X-ray wavelengths was reported, with the optical flux fading at a much greater rate (a factor of 1.7 faster) compared to the previous decay in Sep. - Nov. 2016. On 19th April 2017 the V-band magnitude was V = 18.49 (ATel #10288). Since then, we have continued to monitor the source with the 2-m Faulkes Telescopes North and South, and the 1-m Las Cumbres Observatory (LCO) network of telescopes. We collected multiband photometry in i', R and V bands. We observed a second, unexpected, increase of the optical flux in all covered bands. Indeed, after reaching a minimum of V = 20.49 +- 0.20; R = 19.37 +- 0.06; i' = 19.26 +- 0.09 on 23rd April 2017 (at 23:40-23:50 UT), the source brightened over the next 3.6 days by 1.4, 0.6 and 0.8 mag in V, R and i'-bands respectively, to V = 19.10 +- 0.05; R = 18.81 +- 0.03; i' = 18.45 +- 0.05 on 27th April (14:40-15:00 UT). The optical flux of the source may peak again soon, or keep rising to a new (mini-)outburst, before fading again to quiescence. There is an approved Swift/XRT ToO scheduled for 29th April. Multi-wavelength observations during this re-brightening phase are strongly encouraged. The Faulkes Telescope / LCO observations are part of an on-going monitoring campaign of ~ 40 low-mass X-ray binaries (Lewis et al. 2008). This work makes use of observations from the Las Cumbres Observatory (LCO). Below is a link to the updated light curves of J1753. Swift J1753.5-0127 Faulkes/LCO light curve

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atel_10400

Title: Erratum: ATel#10399 Authors: Paul Luckas (International Centre for Radio Astronomy Research, University of Western Australia) Date: 19 May 2017; 02:39 UT Provenance: S. N. Shore ([email protected]) Subjects: Nova Description: By a mistake of transcription the link for the discovery announcement, "Spectroscopic observations of ASASSN-17gk" (ATel #10399) should refer to ATel#10387 for the discovery. This is also a chance to note that the absence of some indicator lines of the Fe-curtain stage: Si II 4128/30,6347,6371; many of the [Fe II] lines were not yet in emission; and a thorough search for He I lines turned up nothing. The Balmer lines showed symmetric maximum velocities (absorption and emission) and weak asymmetries in the profile with a slight "fat tail" in the red wing. It is the strong D-line absorption alone that suggests this may be a possible dust former, but there was no strong emission component on the Na I resonance doublet.

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atel_10475

Title: Spectroscopic Classification of SN 2017emq as a Type Ia Supernova Authors: Danfeng Xiang, Liming Rui, Han Lin, Xiaofeng Wang (Tsinghua University), Huiyu Yuan, Feng Xiao, Tianmeng Zhang (NAOC), and Jujia Zhang (YNAO) Date: 8 Jun 2017; 02:46 UT Provenance: Xiaofeng Wang ([email protected]) Subjects: Optical, Supernovae, Transient Description: We obtained an optical spectrum (range 370-870 nm) of SN 2017emq(=PS17dfh),discovered by PS1, on UT June 07.54 2017 with the 2.16-m telescope (+BFOSC) at Xinglong Station of National Astronomical Observatories of China (NAOC). The spectrum is consistent with that of a type Ia supernova around the peak brightness. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J., 666, 1024) shows that it matches with SN 2007af at t=0 day from the maximum light. After correcting for a redshift of 0.005 for its host galaxy UGC 5369, an expansion velocity of about 14100 km/s can be derived from the absorption minimum of Si II 635.5 nm line. Our classification spectrum is also posted on the IAU Transient Name Sever: http://wis-tns.weizmann.ac.il/object/2017emq/

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atel_10590

Title: Spectroscopic Classification of AT2017fna with Keck I Authors: Y.-C. Pan, M. R. Siebert, R. J. Foley (UCSC) Date: 21 Jul 2017; 20:25 UT Provenance: Yen-Chen Pan ([email protected]) Subjects: Optical, Supernovae Description: We report the classification of AT2017fna (=ATLAS17ioz) from a spectroscopic observation made on 2017 July 20 UT with the Low Resolution Imaging Spectrometer (LRIS) on the Keck I telescope. The classification was performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes ATLAS17ioz | AT2017fna | 23:46:51.85 | -10:27:32.02 | 0.074 | Ia | -3 d | (1) Notes: When the redshift is given to 2 decimal places, it is derived from the SN spectrum. Otherwise, the redshift is determined from the host galaxy. (1) SN 1991T-like object. We measure a Si II 6355 velocity of -9,700 km/s.

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atel_10725

Title: Rapid re-brightening of galactic nova ASASSN-17hx Authors: A. Kurtenkov, M. Napetova (Institute of Astronomy and NAO, Bulgaria), T. Tomov (Nicolaus Copernicus University, Torun, Poland) Date: 10 Sep 2017; 05:20 UT Provenance: Kiril Stoyanov ([email protected]) Subjects: Optical, Nova Description: Referred to by ATel #: 10736 We report a rapid brightness increase of the slow galactic nova ASASSN-17hx = Nova Scuti 2017 (ATel #10523, #10527, #10542, #10552, #10558, #10572, #10613, #10636, #10641) ~40 days after its maximum. Photometric observations were carried out with the 50/70 cm Schmidt telescope of the Rozhen observatory in Bulgaria. Photometric calibrations in Johnson B and V were done using four bright APASS stars. The following magnitudes were obtained: Date,UT Bmag Vmag Sep 06.82 11.50 10.77 Sep 07.80 10.94 10.20 Sep 08.79 10.55 9.78 Sep 09.84 10.22 9.42 Our previous photometric estimate was B=11.63, V=10.93, on Sep 1.75 UT, which shows a >1.4 mag rise in each band. Each photometric datapoint has been calculated as the median magnitude from 5 consecutive images. All errors are 0.02 mag in V-band and 0.03 mag in B-band. ASASSN-17hx had been slowly decreasing in brightness since its maximum in the end of July. Further photometric observations will show whether we are witnessing the onset of strong GK Per-like oscillations or the rise towards a second strong maximum. This re-brightening also provides the opportunity of obtaining higher-S/N high-resolution spectra before the ground-based visibility window of the object ends towards the end of October.

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atel_10830

Title: SALT-HRS observation of the blazar TXS 0506+056 associated with IceCube-170922A Authors: B. van Soelen (UFS), David A. H. Buckley (SALT/SAAO), Markus Boettcher (NWU) Date: 7 Oct 2017; 13:26 UT Provenance: David Buckley ([email protected]) Subjects: Optical, Neutrinos, Blazar Description: Referred to by ATel #: 10838, 10840, 10844, 10861, 10890 The blazar TXS 0506+056, which has been proposed as the counterpart to the neutrino event IceCube-170922A, has recently been reported to show increased optical and gamma-ray emission (ATel #10817, #10801, #10799, #10794, #10792, #10791, #10787, #10773). We undertook a 2500 second observation of this sources (starting 2017-09-29 01:52 UT) with the Southern African Large Telescope (SALT) using the High Resolution Spectrograph (HRS) in low-resolution mode (R~16000), covering the wavelength range ~3899 - 800 Angstrom. The spectrum is featureless with no indication of the lines from the host galaxy. The only visible lines are the NaD lines from Galactic absorption. This is consistent with observations of a non-thermally dominated blazar and are identical to that reported in ATel #10799.

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atel_10925

Title: Fermi LAT Detection of a GeV Gamma-Ray Flare from the Be-Pulsar Binary System PSR B1259-63 with Rapid Variability Authors: T. J. Johnson (GMU, resident at NRL), K. S. Wood (Praxis Inc., resident at NRL), P. S. Ray (NRL), E. C. Ferrara (UMD/NASA GSFC), M. T. Kerr (NRL), C. C. Cheung (NRL), on behalf of the Fermi Large Area Telescope Collaboration Date: 3 Nov 2017; 21:52 UT Provenance: Tyrel Johnson ([email protected]) Subjects: Gamma Ray, >GeV, Binary, Pulsar Description: Referred to by ATel #: 10972, 10973, 10995, 11028 Using data from the Large Area Telescope (LAT), one of the two instruments on board the Fermi Gamma-ray Space Telescope, we have detected a >100 MeV flare from PSR B1259-63 over the time interval 2017-11-02 01:47:25 UTC to 2017-11-03 06:29:13 UTC with a significance of approximately 10 sigma, a preliminary photon flux (from 100 MeV to 300 GeV) of (3.1 +/- 0.4) x 10^-6 ph/cm^2/s, and a power-law photon index of 2.6 +/- 0.1, quoted uncertainties are statistical only. This follows a less intense flare shortly after periastron (ATel #10818) and prior to periastron (ATel #10775). During the six days prior no significant emission was detected, with flux upper limits of 0.9, 1.1, 0.5, 0.6, 1.0, and 0.7 x 10^-6 ph/cm^2/s. We further split the time interval with significant emission into four 6-hour bins and one 4.7-hour bin and performed likelihood fits in each time bin. We detect a peak flux of (7.6 +/- 1.5) x 10^-6 ph/cm^2/s in the 2017-11-02 13:47:24.0 to 19:47:24.0 UTC time bin. Significant emission was not detected in the final two time bins, with upper limits of 2.7 and 1.2 x 10^-6 ph/cm^2/s, indicating rapid variability. These time-resolved results are in agreement with the aperture photometry reported in ATel #10924. PSR B1259-63 is in a 3.4 yr binary orbit with a Be star. The most recent periastron passage occurred on 2017-09-22, 41 days before the flare reported in this ATel. As noted in ATel #10918, after the two prior periastron passages observed by Fermi, in 2010 and 2014, intense >100 MeV flares were detected starting 30 days after periastron, peaking 36 and 38 days after periastron, respectively, and lasting until 70 days after periastron. Because Fermi operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. In consideration of the expected ongoing activity of this source we strongly encourage multi-wavelength observations. For this source the Fermi LAT contacts are Tyrel Johnson ([email protected]) and Kent Wood ([email protected]). The Fermi LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

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atel_11010

Title: Spectroscopic classification of PTSS-17bazc (SN 2017imx) as a type Ia supernova Authors: J.-J. Zhang, L. Xu (YNAO); X. F., Wang, W.-X., Li (THU); H.-J. Tan (CCU), B. Li, Z.-J. Xu, H.-B. Zhao, L.-F. Wang (PMO); D.-F. Xiang, L.-M. Rui, H. Lin (THU)? Date: 27 Nov 2017; 03:33 UT Provenance: Ju-Jia Zhang ([email protected]) Subjects: Optical, Supernovae Description: We obtained an optical spectrum (range 350-890 nm) of PTSS-17bazc (SN 2017imx),?discovered by the PMO-Tsinghua Supernova Survey (PTSS, http://www.cneost.org/ptss/ ), on UT 2017 Nov. 26.7 with the Li-Jiang 2.4 m telescope (LJT+YFOSC) at Li-Jiang Observatory of Yunnan Observatories. The spectrum is consistent with that of a type Ia supernova at a few days after the maximum light. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, ApJ, 666, 1024) shows that it matches with SN 1995D at t = +10 days from the maximum light. After correcting for a redshift of 0.0687 (via narrow H alpha emission in the spectrum) an expansion velocity of about 9000 km/s can be derived from the absorption minimum of Si II 635.5 nm.

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atel_11070

Title: The optical re-brightening of M31N 2017-09a Authors: Hanjie Tan (Chinese Culture University), David Boyd (BAA VSS), Xing Gao (Xinjiang Astronomical Observatory), Seiichiro Kiyota (VSOLJ), Jingyuan Zhao, Mi Zhang, Guoyou Sun (Xingming Observatory Sky Survey Group), Christopher Lloyd (University of Sussex) Date: 16 Dec 2017; 23:06 UT Provenance: Christopher Lloyd ([email protected]) Subjects: Optical, Nova, Transient Description: We report the optical re-brightening of the Fe II class nova M31N 2017-09a (AT2017glc , PNV J00440872+4143367) which was first reported as a transient by Zhang et al., (2017, TNS Discovery Report) at unfiltered magnitude 18.8 on 2017-08-30.7 UT (JD=2457997.2). On the following night it was magnitude 18.6 and earlier observations put the upper limit of the precursor at magnitude 19.5. Spectroscopy by Williams & Darnley (2017, ATel #10741) taken approximately 11 days later showed broad Balmer emission lines (Hα, Hβ, Hγ) and Fe II emission lines, confirming its classification as a classical Fe II class nova. Unpublished photometry by the Xingming Observatory (IAU code C42), the Sierra Remote Observatory and the West Challow Observatory (IAU code J90) suggest the original outburst peaked at unfiltered magnitude 17.8 around 2017-09-03, faded to below magnitude 19.5 by 2017-09-06 and remained fainter than this until 2017-12-07 when it was seen at magnitude 19.2. The final re-brightening occurred between 2017-12-13.5 UT from magnitude 19.2 and 2017-12-14.5 UT where three observations put the magnitude ~ 18.8. The most recent observations give V = 18.56(7) at 2017-12-14.7 UT and unfiltered magnitude 18.7 at 2017-12-15.1 UT suggesting that the transient is brightening. Further observations are encouraged.

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atel_11175

Title: Spectroscopic Classification of SN 2018gv with Keck I/LRIS Authors: M. R. Siebert, G. Dimitriadis, R. J. Foley (UCSC) Date: 16 Jan 2018; 12:28 UT Provenance: Ryan Foley ([email protected]) Subjects: Optical, Supernovae Description: Referred to by ATel #: 11211 We obtained spectroscopic observations of SN 2018gv with the LRIS spectrograph on the 10-m Keck I telescope on 2018 Jan 16 UT. The spectrum indicates that SN 2018gv is a very young, normal Type Ia supernova. Using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024), we find a good match to several Type Ia SNe 10-15 days before maximum brightness. We note that the small number of SNe Ia observed at very early phases often results in a bias to later phases. The SN was discovered at 16.5 mag, which assuming a distance modulus of 31.1 mag for the host galaxy NGC 2525 (Tully et al., 2013, AJ, 146, 86T), corresponds to an absolute magnitude of -14.8 -- or at least 4 mag below peak brightness. This further indicates that the SN is particularly young. If the SN has minimal host reddening, it will peak at V ~ 12 mag. We measure an Si II 6355 velocity of -16,800 km/s. Similarly, we measure a C II 6580 velocity of -15,300 km/s. We detect narrow Ca H&K absorption at the host-galaxy redshift, but do not detect narrow Na D.

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atel_11250

Title: Optical activity of the X-ray source 1RXS J051439.2-021615 Authors: K. Gazeas (National and Kapodistrian University of Athens) Date: 2 Feb 2018; 17:22 UT Provenance: Kosmas Gazeas ([email protected]) Subjects: Optical, Transient, Variables Description: The X-ray source 1RXS J051439.2-021615 (RA 05h14m39.20s, Dec -02d16m15.00, J2000.0) showed an optical V-band flare, during the night of 25/26 January 2018 (JD=2458114). While the source had a relatively stable luminosity of V=12.84(1) mag during the past days, there was a sudden increase of the observed flux, which started at HJD=2458144.43313 and reached the peak of V=11.85(1) mag at HJD= 2458144.43741 within a few minutes. TYC 4755-59-1 was used as a comparison for the photometric reduction and it was found to be a good standard with V=12.11(1) mag. The observations were obtained in a 3-min cadence and the brightness was increased by 1 mag within 9 minutes with a slope of ~0.11 mag/minute. An exponential decline was observed until the end of the night, when the magnitude dropped from V=11.85(1) mag to V=12.72(1) mag in approximately 45 minutes. Multi-wavelength observations on this X-ray source are highly encouraged, while the robotic and remotely controlled telescope at the University of Athens Observatory (UOAO) will continue to follow the target in BVRI optical bands in the following days. Questions regarding the current flare and data availability should be directed to Dr. Kosmas Gazeas ([email protected]). A light curve sample can be found under the link: http://observatory.phys.uoa.gr/menu_news_events_en.html

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atel_11325

Title: Independent Discovery of an Apparent Nova in M81 Authors: K. Hornoch, H. Kucakova (Ondrejov), S. C. Williams (Lancaster), M. Henze (SDSU), G. Sala, J. Jose (UPC-IEEC), H. Meusinger (TLS), M. J. Darnley (LJMU), A. Kaur, D. H. Hartmann (Clemson), A. W. Shafter (SDSU) Date: 20 Feb 2018; 21:15 UT Provenance: Martin Henze ([email protected]) Subjects: Optical, Nova, Transient Description: The M81 nova monitoring collaboration reports the independent discovery of an apparent nova in M81 on a co-added 2700-s unfiltered CCD frame taken on 2018 Feb. 19.039 UT with the 0.65-m telescope at Ondrejov (OND). Additional R-band photometry is provided from a co-added 4000-s image obtained with the 0.80-m telescope Joan Oro (TJO). The object was first announced and designated AT2018xb by Z. Xu and X. Gao (see here) and is located at R.A. = 9h54m52s.40, Decl. = +69o04'08".5 (equinox 2000.0), which is 218.5" west and 13.4" north of the center of M81 (see link to discovery image below). Here we list the observing dates and corresponding photometry: Date [UT] | Mag | Err | Filter | Telescope 2018-02-14.056 | <22.1 | | C | OND 2018-02-19.039 | 20.4 | 0.2 | C | OND 2018-02-19.936 | 19.4 | 0.1 | C | OND 2018-02-19.972 | 19.9 | 0.4 | R | TJO The OND 0.65-m is a reflecting telescope at the Ondrejov observatory operated jointly by the Astronomical Institute of ASCR and the Astronomical Institute of the Charles University of Prague, Czech Republic. It uses a Moravian Instruments G2-3200 CCD camera (with a Kodak KAF-3200ME sensor and standard BVRI photometric filters) mounted at the prime focus. The Telescopi Joan Oro (TJO) is a 80-cm Ritchey-Chretien F/9.6 telescope at the Observatori Astronomic del Montsec, owned by the Catalan Government and operated by the Institut d'Estudis Espacials de Catalunya, Spain. It uses a Finger Lakes PL4240-1-BI CCD Camera with a Class 1 Basic Broadband coated 2k x 2k chip with 13.5 microns square pixels. The unfiltered OND photometry was calibrated against R-band comparison stars from Perelmuter & Racine (1995). The TJO photometry is based on the SDSS DR7 photometry catalogue. Discovery image

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atel_11425

Title: Optical Spectra of MAXI J1820+070 with Keck Authors: Peter Garnavich and Colin Littlefield (Notre Dame) Date: 16 Mar 2018; 02:41 UT Provenance: Colin Littlefield ([email protected]) Subjects: Optical, Black Hole, Transient Description: Referred to by ATel #: 11426, 11427, 11432, 11437, 11440, 11451, 11478, 11480, 11481, 11510, 11723 We obtained spectra of the new X-ray transient MAXI J1820+070 (ATel #11399) with the Keck I telescope and LRIS spectrograph on March 15.6 (UT). The spectra have a resolution of 3 Ang and cover 3500 to 8000 Ang. The continuum dominates the light, but low-equivalent-width emission features are also seen. We confirm the presence of a broad, asymmetric H-alpha emission line (ATel #11424). We also detect broad H-beta, H-gamma, and H-delta absorption with emission lines in the center, characteristic of an accretion disk in outburst. He II 4686 (with EW = -1.7 Ang) is seen on top of the continuum. We also see deep Ca II interstellar absorption in the blue, suggesting significant extinction along the line-of-sight. We thank Josh and Cynthia at the Keck Observatory for helping to obtain these observations.

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atel_11490

Title: INTEGRAL observations of MAXI J1820+070: public data products Authors: E. Kuulkers (ESA/ESTEC), E. Bozzo, C. Ferrigno (ISDC/University of Geneva), T. Belloni (INAF-OAB), C. Sanchez-Fernandez (ESA/ESAC) Date: 29 Mar 2018; 15:05 UT Provenance: Erik Kuulkers ([email protected]) Subjects: X-ray, Gamma Ray, Binary, Black Hole, Transient, Variables Description: Referred to by ATel #: 11723, 12157 INTEGRAL is performing public Target-of-Opportunity observations of the black-hole binary X-ray transient MAXI J1820+070 (ATel #11399). So far, data have been collected in the period 16-27 March 2018 (see ATels #11478, #11488). INTEGRAL will continue to publicly monitor the source until further notice, interspersed with other observations. As a service to the community, especially meant to help multi-wavelength data comparisons, the INTEGRAL Project is providing ready-to-use scientific data products of all publicly available observations of the source via the INTEGRAL Science Data Centre (University of Geneva, Switzerland). This will be in the form of light curves in 1 energy band for JEM-X1 (3-25 keV) and 2 energy bands for IBIS/ISGRI (25-60 and 60-200 keV). All relevant information and data files can be retrieved from the repository linked at the bottom of this Telegram. We caution that these data products are based on preliminary (near-real time) data and analysis; they will be updated whenever appropriate. We kindly ask anyone making use of these INTEGRAL data products to cite this Telegram. We thank the INTEGRAL Science and Mission Operations Centres for their effort in making these observations possible. http://www.isdc.unige.ch/integral/analysis#QLAsources

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atel_11600

Title: Discovery of DLT18v/AT2018beg with PROMPT and the DLT40 Survey Authors: D. Sand (Arizona), S. Valenti (UC Davis), S. Wyatt (Arizona), S. Yang (INAF-OAPd), D. E. Reichart, J. B. Haislip, V. Kouprianov (UNC) Date: 3 May 2018; 14:14 UT Provenance: David Sand ([email protected]) Subjects: Optical, Supernovae, Transient Description: We report the discovery of DLT18v/AT 2018beg, which was first imaged by the PROMPT5 0.41m telescope located at CTIO on 2018 May 03.35 (UT) at r~17.9 mag during the ongoing D<40 Mpc (DLT40) sub-day cadence supernova search. A confirmation image was obtained on 2018 May 03.52 with the PROMPT telescope at Meckering Observatory, Australia. DLT18v is located at RA: 13:51:20.085 DEC: -48:01:28.86, ~2.5 arcmin from the potential host galaxy ESO 221- G 013. Due to the low galactic latitude of this transient, and its remote location from its potential host, it is also plausibly a Galactic transient. We do not detect the transient on 2018 April 30.3 or in prior imaging of the field. All images were taken in a 'Clear' filter which was calibrated to an approximate r-band magnitude. Further observations are encouraged.

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atel_11670

Title: Optical and Infrared Spectroscopy of Nova Ophiuchi 2018 No.2 Authors: R. J. Rudy, J. C. Mauerhan, R. W. Russell, J. P. Subasavage, S. J. Wiktorowicz, D. L. Kim (Aerospace Corporation.), M. L. Sitko (U. of Cincinnati) Date: 23 May 2018; 21:24 UT Provenance: Richard Rudy ([email protected]) Subjects: Infra-Red, Optical, Nova Description: Over a two week period coming approximately two months after outburst, Nova Ophiuchi 2018, No.2 (CBET 4492) was observed spectroscopically using instruments from three different facilities: 2018 May 6, using the Spex instrument at the Infrared Telescope Facility (0.7-2.5 microns); 2018 May 14, using the Broadband Array Spectrograph System on the 3.6 meter Advanced Electro-Optical Systems telescope (3-13 microns); 2018 May 19, with the VNIRIS spectrograph on the Aerospace Corporation's one meter telescope (0.47-2.5 microns). No significant changes were seen between the May 6 and May 19 observations. Excitation of the emission line gas was fairly low during this period with C I, N I, O I lines were still present in the spectrum and the He I lines just emerging. The strongest emission features were H-alpha and the O I lines at 0.8446 and 1.1287 microns. The latter transitions are excited by Lyman Beta fluorescence and their relative strengths, together with the O I transition at 1.3165 microns, indicate a reddening value of E(B-V) = 0.55 +- 0.15. This extinction is interstellar in origin as there was no indication of dust present in the nova ejecta. Line widths were approximately 1400 km/sec as measured from their full width half maxima.

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atel_11760

Title: Further follow-up of AT2018cow/ATLAS18qqn at Observatoire de Haute Provence Authors: S. Basa (LAM), S. Antier (LAL), M. Boer (Artemis), N. Christensen (Artemis), B. Cordier (CEA), D. Corre (LAM), M. Coughlin (Caltech), D. Coward (UWA), B. Gendre (UWA), X. Han (NAOC), J. Wang (NAOC), A. Klotz (IRAP), N. Leroy (LAL), J. Mao (YNAO), K. Noysena (Artemis), D. Turpin (NAOC), J. Y. Wei (NAOC), C. Wu (NAOC), W. Zheng (UC Berkeley) for GRANDMA team Date: 22 Jun 2018; 16:06 UT Provenance: Sarah Antier ([email protected]) Subjects: Optical, Gamma-Ray Burst, Supernovae, Transient Description: Referred to by ATel #: 11796 We observed the field of ATLAS18qqn/AT2018cow (Smartt et al. ATel #11727) with the SDSS g, r, i and z filters with the robotic IRiS 50-cm telescope at Observatoire de Haute-Provence, France. Observations started on 2018-06-21 20h22 UT during approximately 2 hours, and the weather was partly cloudy at the end of the observations. Observations were taken as follow: 5 min x 6 for each band. We measured AB magnitudes (calibrated with the SDSS R9, but not corrected for host galaxy background contamination) as follows: r_AB = 14.54 +- 0.18 i_AB = 14.37 +- 0.20 These measurements are consistent with our previous observations (Zheng et al., ATel #11743, Wu et al., ATel #11758, Klotz et al., ATel #11757 ) and other photometric reports : Smartt et al. (Atel #11742, #11727), Fremling et al. (ATel #11738), Chen et al. (ATel #11734, #11729)

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atel_11820

Title: A rapid state transition in MAXI J1820+070 Authors: J. Homan (Eureka Scientific and SRON), P. Uttley (Univ. of Amsterdam), K. Gendreau, Z. Arzoumanian (GSFC), M. Saylor (KBRwyle), J. F. Steiner, D. Pasham (MIT), A. L. Stevens (Michigan State Univ.), D. Altamirano (Southampton), E. Kara (Univ. of Maryland). A. C. Fabian (Univ. of Cambridge) for the NICER team Date: 5 Jul 2018; 21:59 UT Provenance: Jeroen Homan ([email protected]) Subjects: X-ray, Black Hole, Transient Description: Referred to by ATel #: 11823, 11827, 11831, 11855, 11887, 11899, 11936, 11951, 12057, 12061, 12064, 12068, 12128, 12157, 14492 We report on ongoing NICER monitoring observations of the black hole transient MAXI J1820+070 (ATel #11399, #11400, #11418, #11423, #11420, #11426). Following a fast rise upon its discovery in March 2018 and an extended hard state plateau, the 0.2-12 keV count rate of the source began a steady decline in mid-May (see link below for light/hardness curves). A reversal of this behavior was observed in mid-June. The NICER X-ray Timing Instrument (XTI) showed a broad minimum (at ~5600 cts/s) yielding to an increase in count rate, along with a softening of the spectrum. This increase and softening have both been accelerating in the past week. On July 5 the average 0.2-12 keV count rate was ~34300 cts/s, up from ~9300 cts/s on June 27. Rapid evolution has also been seen in the power density spectra. The low-frequency QPOs, which have been reported previously (ATel #11488, #11510 #11576, #11578), have increased in frequency from ~0.35 Hz on June 27 to ~3.0 Hz on July 5. To emphasize the rate of evolution, we note that the QPO frequency doubled in less than 18 hours between the July 4 and 5 observations. The spectrum of the July 5 observation is reasonably well described by an absorbed continuum model consisting of a disk component, a power law, and reflection. The slope of the power law (~2.4) is considerably steeper than during the hard state observations of the source (1.6-1.7, ATel #11576). The unabsorbed 0.3-10 keV flux on July 5 was 9.8e-8 erg/cm^2/s. For a distance of 3.2 kpc (Gandhi et al. 2018, arXiv:1804.11349) this corresponds to a luminosity of 1.2e38 erg/s. The above behavior suggests that MAXI J1820+070 is currently in a hard intermediate state and transitioning, at an unusually rapid rate, toward the soft state. Since the soft state may already be reached within a few days, NICER observations of the source are continuing at an intensive rate and we strongly encourage observations at all wavelengths in the coming days to follow this state transition in detail. NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA. Count rate and hardness evolution of MAXI J1820+070

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atel_11940

Title: Spectroscopy and photometry of Nova Oph 2018 N.3 (=PNV J17422408-2053088), still on the rise toward maximum Authors: U. Munari (INAF Padova), P. Valisa, F.-J. Hambsch, A. Frigo (ANS Collaboration Date: 11 Aug 2018; 20:13 UT Provenance: U. Munari ([email protected]) Subjects: Optical, Nova Description: Discovered on Aug 9.112 UT by C. Jacques, J. Barros, E. Pimentel, and P. Holvorcem (Brazilian Transient Search), PNV J17422408-2053088 has been classified as a FeII-type Galactic nova by Williams et al. (ATel #11928) from 2-m Liverpool Telescope spectra obtained on Aug 9.93 UT. The nova has been discovered well before maximum brightness, as shown by the comparison of our BVI photometry for Aug 10 and 11, with that by S. Kiyota as reported on the CBAT "Transient Object Followup Reports" web page: UT| B| V| I ---|---|---|--- Aug 9.359| 11.29| 10.69| 10.07| S. Kiyota Aug 10.018| 10.97| 10.11| 8.90| ANS Aug 11.014| 10.37| 9.45| 8.26| ANS The red colors above suggest significant reddening, as confirmed by the saturated interstellar NaI doublet and the rich assortment of diffuse interstellar bands (DIBs) we have measured on an high resolution Echelle spectrum (4400-9100 Ang, res. pow. 15,000) that we have obtained with the Varese 84cm telescope on Aug 10.839 UT, at the same time when we also recorded a low resolution spectrum (3200-7900 Ang, 2.31 Ang/pix) with the Asiago 1.22m telescope. The equivalent width (E.W.) for interstellar KI 7699 corresponds to E(B-V)=0.94 adopting the calibration of Munari and Zwitter (1997, A&A 318, 269), and the E.W. of DIB 6614 provides E(B-V)=1.01 from Munari (2014, ASPC 490, 183). The E.W. of DIBs at 5780 and 5797 correspond, respectively, to E(B-V)=0.92 and 1.04 applying Kos and Zwitter (2013, ApJ 774, 72) relations. The overall average is E(B-V)=0.98 +/- 0.02. Significant evolution has occurred since the spectral observation by Williams et al. (ATel #11928), primarily a reduction in excitation and in line width and velocity, as usual during the rise to maximum. The HeI lines are gone, and now a greater number of low-excitation emission lines are present over the whole spectral range, all displaying P-Cyg profiles, with the equivalent width of the absorption component rivaling or surpassing the emission one. Lines from a large number of FeII multiplets are present, CaII H and K, near-IR CaII triplet, Balmer and Paschen series, NaI, OI 7772 and 8446 (not yet Bowen pumped). The P-Cyg profiles are now perfectly fitted by a combination of two Gaussians, with no extended wings. The velocity shift from emission of P-Cyg absorptions range now from about -580 km/s for FeII, to -650 for Hbeta, to -710 for OI. The width of emission and absorption components also vary among ions and lines, from 1100 and 760 km/s (respectively) for Hbeta to 730 and 460 km/s for OI.

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atel_12000

Title: INTEGRAL detects a rebrightening of the accreting millisecond X-ray pulsar IGR J17591-2342 Authors: C. Sanchez-Fernandez (ESAC, ESA), C. Ferrigno, J. Chenevez, E. Kuulkers, R. Wijnands, A. Bazzano, P. Jonker, M. Del Santo, on behalf of the INTEGRAL Galactic bulge monitoring team Date: 1 Sep 2018; 11:24 UT Provenance: Celia Sanchez-Fernandez ([email protected]) Subjects: X-ray, Gamma Ray, Binary, Neutron Star, Transient, Pulsar Description: Referred to by ATel #: 12004 IGR J17591-2342 was discovered by INTEGRAL on August 11, 2018 (ATel #11941). The outburst had actually started on July 22, 2018 (ATel #11981) and reached its peak on July 25, with a flux of ~50mCrab in the Swift/BAT energy range (15-150 keV). Since then, the outburst smoothly decayed to lower flux values, being detected at a flux of 3 mCrab by NICER (2-10 keV) on August 15th (ATel #11957). During observations of the Galactic Bulge region between August 30, 21:10 and August 31, 00:52 (UT), a significant rebrightening of the source has been detected by IBIS/ISGRI. The flux estimated from the mosaic image is ~33 mCrab in the 20-40 keV energy range. The source is barely at the edge of the JEMX field of view. We derive 3-sigma upper limits of ~20 mCrab (3-10 keV) and ~40 mCrab (10-25 keV) in the JEM-X mosaics. The IBIS/ISGRI spectrum can be fit with a powerlaw model with spectral index 2, showing no significant spectral variations when compared to the IBIS/ISGRI spectrum of the system measured on August 11. INTEGRAL will be observing the region around this source until September 4th. We encourage observations at other wavelengths.

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atel_12090

Title: MASTER-OAFA: new OT, ampl>6.5m Authors: V. Shumkov, V. Lipunov (Lomonosov MSU), R. Podesta (OAFA), H. Levato (ICATE), D. Buckley (SAAO), C. Lopez, F. Podesta, C. Francile (OAFA, SanJuan National University), E. Gorbovskoy, N. Tiurina, P. Balanutsa, A. Kuznetsov, V. Kornilov, V. Chazov, D. Vlasenko, V. Vladimirov, O. Gress, A. Krylov (Lomonosov Moscow State University, SAI), R. Rebolo Lopez, M. Serra-Ricart ((IAC), T. Pogrosheva, V. Senik, A. Gabovich Date: 9 Oct 2018; 08:41 UT Provenance: Nataly Tyurina ([email protected]) Subjects: Optical, Ultra-Violet, Request for Observations, Cataclysmic Variable, Transient, Variables Description: MASTER OT J055548.92-303053.3 discovery - ampl>6.5mag, no known optical source in VIZIER MASTER-OAFA auto-detection system ( Lipunov et al., "MASTER Global Robotic Net", Advances in Astronomy, 2010, 30L ) discovered OT source at (RA, Dec) = 05h 55m 48.92s -30d 30m 53.3s on 2018-10-09.22942 UT. The OT unfiltered magnitude is 15.5m (mlim=18.6m). The OT is seen in 3 images (2018-10-09 05:25:11,05:30:22,08:24:20.10). There is no minor planet at this place. We have reference image without OT on 2017-11-23.29399 UT with 19.2m unfiltered magnitude limit (MASTER-OAFA), the nearest in time is reference image on 2018-09-21 00:49:34 with 2018-09-21 00:46:22 (MASTER-SAAO) with unfiltered mlim=20.0 There is no known optical sources in VIZIER database (22m POSS limit in history and more then 6.5m of current outburst amplitude, so as MASTER_W=0.2B+0.8R calibrated by USNO-B1 thousands field stars), but there is GALEX source Spectral observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/055548.92-303053.3.png List of Optical Transients discovered by MASTER MASTER Global Robotic Net

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atel_12150

Title: ePESSTO spectroscopic classification of optical transients Authors: E. Congiu (Padova), M. Berton (FINCA), S. Benetti (Padova), A. Fiore (Padova), A. Pastorello (Padova), A. Reguitti (Padova), L. Tomasella (Padova), C. Barbarino (Stockholm), M. Fraser (UCD), S. C. Williams (Lancaster), C. Inserra (Southampton), E. Kankare (QUB), K. Maguire (QUB), S. J. Smartt (QUB), D. R. Young (QUB), O. Yaron (Weizmann), I. Manulis (Weizmann) Date: 31 Oct 2018; 11:49 UT Provenance: Andrea Pastorello ([email protected]) Subjects: Optical, Supernovae, Transient Description: ePESSTO, the extended Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A&A, 579, 40; http://www.pessto.org ), reports the following supernova classification. The target was supplied by the Backyard Observatory Supernova Search (BOSS; http://bosssupernova.com/ ), and selected from the IAU TNS list (see https://wis-tns.weizmann.ac.il/). The observation was performed on the ESO New Technology Telescope at La Silla on 2018 October 31.31 UT, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution). The classification was done with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and GELATO (Harutyunyan et al., 2008, A&A, 488, 383). Classification spectra and additional details can be obtained from http://www.pessto.org (via WISeREP) and the IAU Transient Name Server. Survey Name | IAU Name | RA (J2000) | Dec (J2000) | Disc. Date | Source | Discovery Mag. | z | Type | Phase | Notes | SN 2018hmy | 08:31:36.39 | -59:47:08.80 | 2018-10-21.65 | BOSS | 16.8 (clear) | 0.021562 | Ia | 2-3 weeks | (1) (1) The spectrum matches that of a normal Type Ia SN 2-3 weeks after the B-band maximum. The ejecta velocity, obtained from the wavelength of the Si II 635.5 nm minimum, is about 9500 km/s. The redshift of the host galaxy ESO 124-G018 is from West et al. 1981, A&AS, 46, 57.

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atel_12240

Title: Classification of SN 2018ivc (=DLT18aq) as a Young Type II Supernova Authors: Xinhan Zhang (Tsinghua University), Jujia Zhang, Xiaoli Wang (YNAO), Xiaofeng Wang, Hanna Sai, Han Lin, Danfeng Xiang, Liming Rui (Tsinghua Univeristy), Yue Wang, Junbo Zhang, Tianmeng Zhang, Huijuan Wang (NAOC) Date: 25 Nov 2018; 01:17 UT Provenance: Xiaofeng Wang ([email protected]) Subjects: Optical, Supernovae, Transient Description: Referred to by ATel #: 12289 We obtained optical spectra (range 360-870 nm) of SN 2018ivc(=DLT18aq) in M77, discovered by DLT40, on UT October 24.5 and 24.7 2018 with the Xinglong 2.16-m telescope (+BFOSC) of National Astronomical Observatories of China (NAOC) and Lijiang 2.4-m telescope at Gaomeigu Station of Yunnan Astronomical Observatories (YNAO), respectively. The spectra are consistent with that of a young type II supernova that suffered significant host-galaxy reddening, with the equivalent width of the Na I absorption being measured as about 2.5 Angstrom. A prominent absorption feature detected at around 627.0 nm can be due to the Ha line. The narrow Ha emission supposed on the continuum seems to show a double peak structure, with an FWHM velocity of 1200 km/s. Adopting a redshift of 0.0038 for the host galaxy (Huchra et al. 1999, ApJS,121, 287), an expansion velocity of 13500 km/s can be inferred for this SN. Followup observations are encouraged.

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atel_12350

Title: INT WFC multi-band photometric follow up of the superluminous supernova SN 2018gft Authors: M. Mallorquin (ULL), E. M. Garcia-Zamora (ULL), A. Hernandez-Garcia (ULL & IAC), A. Alvarez-Hernandez (ULL), A. Alvarez-Saavedra (ULL), P. Carro-Portos (ULL), E. A. Diaz-Suarez (ULL), R. M. Doblas-Cabezas (ULL), M. Fernandez-Torreiro (ULL), J. E. Mendez-Delgado (ULL & IAC), D. Moral-Pombo (ULL), M. A. Nuñez-Cagigal (ULL & IAC), G. Panizo-Espinar (ULL), J. Sanchez-Sierras (ULL), D. SanJulian-Jacques (ULL), H. Villegas-Beberide (ULL), L. Monteagudo (ING), and I. Perez-Fournon (ULL & IAC) Date: 2 Jan 2019; 14:21 UT Provenance: Ismael Perez-Fournon ([email protected]) Subjects: Optical, Supernovae Description: We report multi-band photometry of the superluminous supernova SN 2018gft (= ZTF18abshezu) (= ATLAS18uym) based on CCD images taken with the Wide Field Camera of the Isaac Newton Telescope (Observatorio del Roque de los Muchachos, La Palma), from 2018 Oct 13.918 UT to 13.944 UT. According to the magnitudes we report below, SN 2018gft was about 1.7 magnitudes brighter during our observations than at the epoch of the first ZTF detection. This supernova was discovered on 2018/09/02.335 by the ZTF survey and reported to TNS by C. Fremling et al. It was classified as SN Type SLSN-I at a redshift of z=0.23 by A. Dugas et al. (ATel #12051) from spectroscopic follow-up with the Spectral Energy Distribution Machine (SEDM) mounted on the Palomar 60-inch (P60) telescope (Blagorodnova et. al. 2018, PASP, 130, 5003). It was also detected by ATLAS (ATLAS18uym, TNS). We report here the SN position, based on the INT images, calibrated using the Gaia DR2 catalog: RA (J2000) = 23:57:17.933, Dec (J2000) = -15:37:53.37. The INT Wide Field Camera magnitudes of SN 2018gft, calibrated using Pan-STARRS1 are: g = 17.96 +/- 0.02 (2018 Oct 13.935), exposure time = 3 x 180 seconds r = 18.10 +/- 0.02 (2018 Oct 13.932), exposure time = 3 x 180 seconds i = 18.32 +/- 0.03 (2018 Oct 13.928), exposure time = 3 x 180 seconds The host galaxy is not detected in the Pan-STARRS1 DR1 images (see this comparison with our INT WFC r-band image) and the brightness of the SN does not allow us to detect a faint host galaxy at the position of the SN in the INT WFC images. The light curve of SN 2018gft, from ZTF detections, represented in Lasair #ZTF18abshezu (see also MARS) shows, as expected for a SLSN-I, a very broad peak. The INT WFC observations were carried out close to peak of the light curve in the interval without ZTF observations due to ZTF maintenance. Based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. We thank David Bishop for his wonderful compilation of extragalactic novae and supernovae. SN 2018gft Isaac Newton Telescope Wide Field Camera r-band image

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atel_12425

Title: MAXI/GSC discovery of a new X-ray transient MAXI J1348-630 Authors: F. Yatabe (RIKEN), H. Negoro, M. Nakajima, A. Sakamaki, W. Maruyama, M. Aoki, K. Kobayashi (Nihon U.), T. Mihara, S. Nakahira, Y. Takao, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, T. Hashimoto, A. Yoshida (AGU), N. Kawai, M. Sugizaki, Y. Tachibana, K. Morita (Tokyo Tech), S. Ueno, H. Tomida, M. Ishikawa, Y. Sugawara, N. Isobe, R. Shimomukai, T. Midooka (JAXA), Y. Ueda, A. Tanimoto, T. Morita, S. Yamada, S. Ogawa (Kyoto U.), Y. Tsuboi, W. Iwakiri, R. Sasaki, H. Kawai, T. Sato (Chuo U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, K. Hidaka, S. Iwahori (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), M. Shidatsu (Ehime U.), and Y. Kawakubo (LSU) Date: 26 Jan 2019; 05:18 UT Provenance: Hitoshi Negoro ([email protected]) Subjects: X-ray, Transient Description: Referred to by ATel #: 12430, 12434, 12439, 12441, 12447, 12448, 12456, 12457, 12470, 12477, 12480, 12491, 12497, 12505, 12520, 12829, 12838, 13188, 13451, 13459, 13465, 13539, 13710, 13994, 14016 The MAXI/GSC nova alert system triggered on an uncatalogued X-ray transient source at 03:16 UT on 2019 January 26. Assuming that the source flux was constant over four transits from 21:05 on Jan. 25 to 03:16 on Jan. 26, we obtain the source position at (R.A., Dec) = (207.053 deg, -63.068 deg) = (13 48 12, -63 04 04) (J2000) with a statistical 90% C.L. elliptical error region with long and short radii of 0.42 deg and 0.34 deg, respectively. The roll angle of the long axis from the north direction is 36.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scans was 47 +- 8 mCrab (4.0-10.0keV, 1 sigma error). The source flux has been increasing since 21:05 on January 25, and judging from color images of the MAXI nova-alert system the source spectrum is likely hard. Since there is no known bright X-ray source in the error region above and the source is located on the galactic plane at (l, b) = (309.3, -0.9), the source is very likely a new X-ray nova, and we name the source MAXI J1348-630. Followup observations are strongly encouraged to reveal the nature of the source. Nova alert information of MAXI J1348-630

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atel_12500

Title: Spectroscopic Classifications of Optical Transients with SOAR Authors: M. R. Siebert, D. A. Coulter, J. S. Brown, G. Dimitriadis, R. J. Foley (UCSC) Date: 12 Feb 2019; 23:31 UT Provenance: Matthew Siebert ([email protected]) Subjects: Optical, Supernovae Description: We report the following classification of an optical transient from spectroscopic observations with the Goodman spectrograph on the Southern Astrophysical Research (SOAR) telescope. The target was supplied by Gaia. All observations were made on 2019 February 12 UT. Classifications were performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes Gaia19amg | AT2019aox | 04:12:15.000| -06:42:09.29 | 0.031 | Ia | -3 d | (1) Notes: When the redshift is given to 2 decimal places, it is derived from the SN spectrum. Otherwise, the redshift is determined from the host galaxy. (1) We measure an Si II 6355 velocity of -11,300 km/s.

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atel_12570

Title: Photometric follow-up of blazar TXS 1515-273 with GROWTH-India Authors: Viraj Karambelkar (IITB), Harsh Kumar (IITB), Gaurav Waratkar (IITB), Shubham Srivastav (IITB), Urgain Stanzin (IAO), Varun Bhalerao (IITB), G. C. Anupama (IIA) Date: 13 Mar 2019; 00:27 UT Provenance: Shubham Srivastav ([email protected]) Subjects: Optical, Blazar Description: Referred to by ATel #: 12575 We report photometric observations of the flaring blazar TXS 1515-273 (ATels #12565, #12532, #12537, #12552) with the 0.7 meter GROWTH-India telescope. The magnitudes in the g, r and i filters, calibrated against PS1 reference stars in the field, are as follows: MJD Filter Magnitude 58549.85 g 16.13 ± 0.02 58549.86 r 15.64 ± 0.02 58549.87 i 15.25 ± 0.03 58550.85 g 16.20 ± 0.02 58550.86 r 15.65 ± 0.01 58550.87 i 15.26 ± 0.02 58551.86 g 16.25 ± 0.02 58551.87 r 15.69 ± 0.01 58551.87 i 15.29 ± 0.04 58552.85 g 16.19 ± 0.03 58552.85 r 15.63 ± 0.02 58552.86 i 15.20 ± 0.03 GROWTH-India is a 0.7 meter telescope set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB), with support from the Indo-US Science and Technology Forum (IUSSTF) and the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST), Government of India (https://sites.google.com/view/growthindia/). It is located at the Indian Astronomical Observatory (IAO) at Hanle, Ladakh (India).

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atel_12630

Title: AMI-LA 15.5 GHz observation of the Black Hole candidate XTE J1908+094 Authors: David Williams, Sara Motta, Rob Fender (Oxford), David Titterington, Dave Green (Cambridge), Yvette Perrott (VUW) Date: 5 Apr 2019; 13:47 UT Provenance: Sara Elisa Motta ([email protected]) Subjects: Radio, X-ray, Binary, Black Hole, Transient Description: Following the detection of activity from the Black Hole candidate XTE J1908+094 with INTEGRAL (ATel #12628), we observed the source in the radio band with the Arcminute Microkelvin Imager Large Array (AMI-LA; Zwart et al. 2008; Hickish et al. 2018) at 15.5 GHz on 2019-04-05.2 for 1 hour. The custom pipeline REDUCE_DC (e.g. Perrott et al. 2015) was used to calibrate and flag the data, with 3C286 as the absolute flux calibrator and J1856+0610 as the interleaved phase calibrator. We performed a preliminary analysis of the data and we detect a source at the phase center with peak flux density 1.66mJy/beam, consistent with being the radio counterpart to XTE J1908+094. The rms noise in the image is 0.3mJy/beam, which is significantly higher than expected due a bright contaminating radio source on the edge of the telescope primary beam. We plan to continue monitoring this source and would like to thank the MRAO staff for carrying out these observations.

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atel_12720

Title: IMSNG early detection of AT 2019ein/ATLAS19ieo Authors: Myungshin Im, Gu Lim, Gregory S.-H. Paek, Changsu Choi, (Seoul National University), Hyun-Il Sung (KASI), on behalf of the IMSNG team Date: 3 May 2019; 05:15 UT Provenance: Myungshin Im ([email protected]) Subjects: Optical, Supernovae, Transient Description: As a part of the Intensive Monitoring Survey of Nearby Galaxies (IMSNG; Im et al. 2019, JKAS, 52, 11), we have been doing daily monitoring the field including the location of AT 2019ein /ATLAS 19ieo (Tonry et al. 2019, TNSTR 33987). Our inspection of the R-band images taken at the Mt. Lemmon Optical Astronomy Observatory (LOAO) in Tucson, AZ, and the SNU Astronomical Observatory (SAO) 1m telescope reveals that the transient was not present in the SAO R-band image taken at 2019-04-29 18:07:15 (UT), but appeared in the LOAO B and R-band images taken at 2019-05-01 10:29:38 (UT) with the magnitude consistent with the early report (Smith et al. 2019, ATel #12710). This is about two hours before the first reported detection of AT2019ein by Smith et al (2019, ATel #12710). About 16.5 hours after, AT 2019ein brightened by 0.5 +- 0.1 magnitude in the R-band image taken by the SAO 1m telescope, consistent with the report that this is a very young supernova from spectroscopy (Burke et al. 2019, ATel #12719). Further observations are ongoing.

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atel_12810

Title: LJT Spectroscopic Classification of PTSS-19cmsa(AT2019fzl) as a Type Ia Supernova Authors: J.-J., Zhang, K.-X., Lu, J.-M., Bai (YNAO); H.-J., Tan(NCU); W.-X., Li(THU), B., Li(PMO); Z.-J., Xu; X.-F., Wang(THU), H-B., Zhao(PMO); L.-F., Wang(PMO/TAMU) Date: 28 May 2019; 14:54 UT Provenance: Ju-Jia Zhang ([email protected]) Subjects: Optical, Supernovae Description: We obtained an optical spectrum (range 350-880 nm) of PTSS-19cmsa(AT2019fzl), discovered by the PMO-Tsinghua Supernova Survey (PTSS), on UT May 27.73 2019 with the Lijiang 2.4-m telescope (LJT + YFOSC) at the Lijiang Observatory of Yunnan Observatories (YNAO). The spectrum is consistent with a type Ia supernovae around the maximum light. Cross-correlation with the comparison tool GELATO (Harutyunyan et al. 2008, A&A, 488, 383, https://gelato.tng.iac.es) shows that it matches with SN 1981B at t = +0.7 days from the maximum light. After correcting for a redshift of 0.08346 (via SDSS) for its host galaxy SDSS J152706.83+023430.7, an expansion velocity of about 12000 km/s can be derived from the absorption minimum of Si II 635.5 nm line. It is the 200th supernovae candidates classified by LJT+YFOSC. We acknowledge the support of the staff of the LJT. Funding for the LJT has been provided by the Chinese Academy of Sciences and the People's Government of Yunnan Province.

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atel_12925

Title: Discovery of an Apparent Nova in M31 Authors: K. Hornoch, H. Kucakova (Astronomical Institute, Ondrejov, Czech Republic) Date: 11 Jul 2019; 22:05 UT Provenance: Allen W. Shafter ([email protected]) Subjects: Optical, Nova, Transient Description: We report the discovery of an apparent nova in M31 on a co-added 720-s R-band CCD frame taken on 2019 Jul. 11.079 UT with the 0.65-m telescope at Ondrejov. Subsequently we found the object also on two prediscovery R-band images taken on Jul. 8.007 and 8.068 with the same instrumentation under poor seeing conditions. The object designated PNV J00430090+4119194 is located at R.A. = 0h43m00s.90, Decl. = +41o19'19".4 (equinox 2000.0), which is 186.8" east and 190.9" north of the center of M31 (see link to discovery image below). Please note that the positions have larger uncertainty than typically due to proximity of a bright star. The following R-band magnitudes were obtained using the 0.65-m telescope at Ondrejov: 2019 Jul. 4.057 UT, [18.9; 6.995, [18.0; 8.007, 16.3 ± 0.5 (prediscovery); 8.068, 15.9 ± 0.5 (prediscovery); 11.079, 17.3 ± 0.5. We thank M. Wolf for acquiring images on Jul. 6.995 UT. Discovery image

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atel_12975

Title: SOAR and SALT spectroscopic follow up of V1047 Cen (Nova Cen 2005) Authors: E. Aydi, J. Strader, L. Chomiuk, A. Kawash, K. V. Sokolovsky, L. Shishkovsky (MSU) D. A. H. Buckley (SAAO), M. Orio (INAF Padova, UoW) P. Mroz (Warsaw U. Observatory), P. Woudt (UCT), D. P. K. Banerjee (Physical Research Laboratory, Ahmedabad), A. Evans (Keele University), T. R. Geballe (Gemini Observatory), F-J. Hambsch (VVS, BAV, AAVSO), S. Kafka (AAVSO), U. Munari (INAF Astronomical Observatory, Padova), G. Myers (AAVSO), K. L. Page (U. Leicester, UK), S. Starrfield (ASU), F. Walter (Stonybrook), R. D. Gehrz, C. E. Woodward (Minnesota), and R. M. Wagner (OSU, LBT Observatory) Date: 1 Aug 2019; 17:50 UT Provenance: Elias Aydi ([email protected]) Subjects: Optical, Binary, Cataclysmic Variable, Nova, Star, Transient, Variables Description: Nova Cen 2005 (V1047 Cen) was noticed as an optical transient AT2019hik/Gaia19cfn on 2019-06-10 while showing an unexpected long-term rise in brightness that started as early as 2019-04-06 (ATel #12876) and continues up to this moment. The initial spectroscopic observations (ATel #12885, #12893, #12923) suggested that the re-brightening is a slow dwarf nova outburst, similar to the ones displayed by GK Per. The long 8.66 h orbital period suggested from TESS observations (ATel #12889) seemed to fit this picture. On 2019-07-28.97 UT, we obtained two spectra of low (R ~ 900) and medium (R ~ 5000) resolution using the Goodman spectrograph on the 4.1 m SOAR telescope. On 2019-07-29.73UT we also obtained a 2 x 1000 s spectra using the High Resolution Spectrograph (HRS; Crause et al. 2014, Proc. SPIE, 91476) mounted on the 11m Southern African Large Telescope under the SALT Large Science Program on Transients. The observations were taken in the LR mode of HRS which covers the spectral range of 3800-8900 A at a resolution of R=14000. The SALT spectra were reduced using the SALT HRS MIDAS pipeline (Kniazev et al. 2016, MNRAS 459, 3068). The spectra show broad emission lines of H I, He I, C IV, and [O III] (as reported in ATel #12885, 12893, 12923). However, the Balmer lines have became significantly stronger than the [O III] lines, in comparison with the previous observations (the peak of Hbeta is comparable to [O III] 5007, while Halpha's peak is 5 times stronger; see below a comparison between the line flux ratios). We measure a FWZI > 5000 km/s for the Balmer lines, while the central emission of these lines show a significant broadening in comparison to previous observations. We also identify P Cygni profiles in some of the He I and H I lines at velocities ~ -1200 km/s (as reported in ATel #12893). The broadening of the Balmer lines along with the ongoing brightening of the system are unusual and worth further investigations. We encourage follow up observations in all bands. June 19, 2019: F(Hbeta/[OIII]5007) ~ 0.35 F(Halpha/[OIII]5007) ~ 3.07 July 28, 2019: F(Hbeta/[OIII]5007) ~ 1.58 F(Halpha/[OIII]5007) ~ 15.0

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atel_13025

Title: Rebrightening of MAXI J1820+070 (ASASSN-18ey) in X-rays Authors: Yanjun Xu (Caltech), Fiona Harrison (Caltech) and John Tomsick (UCB/SSL) Date: 14 Aug 2019; 05:53 UT Provenance: Yanjun Xu ([email protected]) Subjects: X-ray, Black Hole, Transient Description: Referred to by ATel #: 13041, 13044, 13066, 13502, 14492 Following the report of steady optical rebrightening of the black hole X-ray transient MAXI J1820+070 (ASASSN-18ey) on August 10, 2019 (ATEL #13014), Swift observed MAXI J1820+070 with XRT twice at August 11 UT 16:12 and August 13 UT 12:40. Fitting the Swift XRT data with an absorbed power-law model (with nH fixed at 1.5e21 cm^-2), we measure the 0.5-10.0 keV flux of (4.5+/-1.4)e-13 erg/cm^2/s and (2.1+/-0.3)e-12 erg/cm^2/s for the first and second observation, respectively. This indicates a rapid brightening of MAXI J1820+070 in X-rays, with a flux increase by ~5 times in less than 2 days. The delay between the optical and X-ray brightening is expected from disk instability models and can be used to infer where the outburst began in the accretion disk (Orosz et al. 1997). We have requested further Swift XRT monitoring of MAXI J1820+070. The rise of MAXI J1820+070 (ASASSN-18ey) in the X-ray band provides encouragement for coverage at other wavelengths.

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atel_13110

Title: Outburst of Comet 29P/Schwassmann-Wachmann Authors: Dennis Bodewits (Auburn U), Michael S. P. Kelley (U. Maryland), Quanzhi Ye (U. Maryland), on behalf of the Zwicky Transient Facility Collaboration Date: 14 Sep 2019; 17:45 UT Provenance: Dennis Bodewits ([email protected]) Subjects: Optical, Comet Description: Referred to by ATel #: 13164, 14207 We report on a rapid increase in the brightness of comet 29P/Schwassmann-Wachmann from images acquired with the Zwicky Transient Facility (ZTF) operated on the 1.2-m Oschin Schmidt telescope at Palomar Observatory. The comet's brightness has been steadily decreasing since previously reported outburst that started around between 2019 Aug 1.50 and Aug 2.44 UT (ATel #12994) until it reached an apparent minimum around Aug 30 - Sep. 1 - 11 UT of r = 16.56 ± 0.04 within a circular aperture of 20,000 km at the position of the comet. A small outburst of 0.2 - 0.3 R-mag was first reported by Charles Bell (priv. comm.) on Sep 6.33 UT and is present in our observation acquired on Sep. 7.42 UT as a 0.12 ± 0.06 r-mag increase. The comet was back to its baseline activity on Sep. 11.42, but an i-mag of 15.82 ± 0.03 was measured on Sep. 12.40 UT, corresponding to an r-mag of 16.06 ± 0.4, indicating a rapid brightness increase of Δ r-mag = 0.49 ± 0.06. This event started between Sep. 11.42 and Sep. 12.40 UT. For the color correction, we assumed median comet color corrections from Solontoi et al. (2010) of g-r = 0.57 and r-i = 0.24. Date UT | Mag | Δ mag | Band | mag r | Δ mag r ---|---|---|---|---|--- 2019 Sep. 12.40 | 15.82 | 0.03 | i | 16.06 | 0.04 2019 Sep. 11.42 | 17.12 | 0.04 | g | 16.55 | 0.05 2019 Sep. 7.42 | 16.20 | 0.03 | i | 16.44 | 0.04 2019 Sep. 1.43 | 17.16 | 0.03 | g | 16.59 | 0.04

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atel_13200

Title: Spectroscopic Classification of AT2019rra as a Type IIP Supernova Authors: Chien-Hsiu Lee (NSF's OIR Lab), Monika Soraisam (UIUC), Gautham Narayan (UIUC), Thomas Matheson (NSF's OIR Lab), Abhijit Saha (NSF's OIR Lab), Arizona-NOAO Temporal Analysis and Response to Events System (ANTARES) team, Thomas G. Brink, Kishore C. Patra, Thomas de Jaeger, WeiKang Zheng, Benjamin E. Stahl, Alexei V. Filippenko (UC Berkeley), Daniel Muthukrishna (University of Cambridge) Date: 18 Oct 2019; 16:48 UT Provenance: Chien-Hsiu Lee ([email protected]) Subjects: Optical, Transient Description: We report the classification of AT2019rra from spectroscopic observations with the Kast spectrograph on the 3 m Shane telescope at Lick Observatory. The optical spectra were obtained on 2019 October 8 UT. Targets were flagged and supplied by ANTARES (antares.noao.edu) and our customized filter as promising stellar explosion events. Classification was performed with DASH (Muthukrishna et al. 2019, arXiv:1903.02557). The light curve of AT2019rra can be found at:https://antares.noao.edu/alerts/data/260084901 . Name | IAU Name | RA (J2000) | Dec (J2000) | MJD | z. | Type | Phase | Notes ZTF19acbwmqd | AT2019rra | 16:38:39.37 | +33:40:41.44 | 58764.15 | 0.037 | IIP | near max. | (1) Note: (1) AT2019rra was also reported to TNS by ALeRCE as a candidate supernova, associated with galaxy SDSS J163839.41+334042.1 with a photo-z of 0.087. However, using the H-alpha emission line from the host galaxy in the Kast spectrum we derived a redshift of 0.037.

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atel_13260

Title: Optical spectroscopy of MAXI J0637-430 confirms a new low-mass X-ray binary Authors: J Strader, E Aydi, K Sokolovsky, L Shishkovsky (Michigan St) Date: 4 Nov 2019; 16:37 UT Provenance: Jay Strader ([email protected]) Subjects: Optical, Binary, Black Hole, Neutron Star, Transient Description: Referred to by ATel #: 13275, 13291, 13292, 13296, 13454, 13779 On 2019 Nov 3, the new soft X-ray transient MAXI J0637-430 was announced (ATel #13256), with a bright candidate optical counterpart was identified in Swift data (ATel #13257). We obtained spectroscopy of this source on UT 2019 Nov 4.2 with the Goodman Spectrograph on the SOAR telescope. We took both a low resolution spectrum (wavelength range 3800-7800 A, resolution 5.6 A) and a moderate resolution spectrum (5500-6750 A, resolution 1.7 A). The low resolution spectrum shows strong, broad, clearly double-peaked H-alpha and He II 4686 emission at Galactic velocities, with weaker emission from H-beta, H-gamma, and He I 5875 and 6678. The Bowen blend is not visible. In the medium resolution spectrum, the H-alpha has a FWHM of about 1740 km/s and an equivalent width of about 5 Ang. No absorption lines conceivably associated with the binary are seen. The spectrum is very blue, with a spectral slope (in lambda--f_lambda) of ~ -3.22 after correcting for the modest foreground reddening of E(B-V) ~ 0.064 (Schlafly & Finkbeiner, 2011, ApJ, 737, 103). Consistent with this low reddening, no clear interstellar absorption lines are present in the spectra, other than perhaps a hint of Na D. These spectroscopic properties provide strong evidence that MAXI J0637-430 is a new low-mass X-ray binary in outburst.

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atel_13350

Title: MASTER: outburst detection with ampl>5.1m Authors: O. Gress, E. Gorbovskoy, V. Lipunov (Lomonosov MSU), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), V. Kornilov, N. Tiurina, P. Balanutsa, I. Gorbunov, E. Minkina, A. Kuznetsov, V. Vladimirov, T. Pogrosheva, D. Vlasenko, D. Zimnukhov, D. Cheryasov, V. Senik, V. Shumkov(Lomonosov MSU), R. Podesta, C. Lopez, F. Podesta, C. Francile (OAFA), H. Levato(ICATE), D. Buckley(SAAO), O. A. Gres, N. M. Budnev, O. Ershova(ISU, API), A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory),V. Yurkov, A. Gabovich, Yu. Sergienko(Blagoveschensk ESU) Date: 14 Dec 2019; 12:49 UT Provenance: Nataly Tyurina ([email protected]) Subjects: Optical, Request for Observations, Cataclysmic Variable, Transient, Variables Description: MASTER OT J064829.56+021205.9 discovery- preliminary dwarf nova outburst with ampl>5.1 MASTER-IAC auto-detection system discovered OT source at (RA, Dec) = 06h 48m 29.56s +02d 12m 05.9s on 2019-12-14.17137 UT. The OT unfiltered magnitude is 16.9m (limit 17.5m). The OT is seen in 2 images. There is no minor planet at this place. We have reference image without OT on 2018-04-03.85720 UT with unfiltered magnitude limit 19.1m. There is no USNO-B1 sources, so the amplitude of outburst is more then 5.1m (but there is PanSTARRs star witt rmag=21.076 in VIZIER database Spectral observations are required. The discovery and reference images are available at: http://master.sai.msu.ru/static/OT/064829.56021205.9.png MASTER Global Robotic Net

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atel_13410

Title: The Continued Unprecedented Fading of Betelgeuse Authors: Edward F. Guinan and Richard J. Wasatonic (Villanova University) Date: 20 Jan 2020; 17:50 UT Provenance: Edward Guinan ([email protected]) Subjects: Infra-Red, Optical, Star, Variables Description: Referred to by ATel #: 13439, 13512 We report further on the recent unusual dimming of the red supergiant Betelgeuse (alpha Ori) reported previously in ATel #13341 and ATel #13365. We continue to carry out V-band and Wing TiO and near-IR photometry of the star. Since our last report, Betelgeuse has continued to gradually decrease in brightness. Our most recent photometry secured on 17.25 UT and 18.20 UT January 2020 yields: V = +1.494 mag and 1.506 mag, respectively. This is more than ~0.2 mag fainter than previously reported in ATel #13365 on 22.25 UT Dec. 2019. However during the last week or so the decline in brightness of the star may be slowing. As reported by Brian Skiff of Lowell Observatory (priv. commun.) visual estimates of Betelgeuse are available as far back as about 180-years ago. Systematic visual measures of the star have been made by AAVSO observers since the 1920s. More precise photoelectric photometry began nearly 100 yrs ago but systematic (mostly unpublished) photometry of Betelgeuse commenced about 40-years ago at Villanova Observatory by Scott Wacker and Guinan. Betelgeuse is now nearly as faint as (the slightly variable) B2 star Bellatrix (V ~+1.62 mag). Bellatrix (gamma Ori) is about 5° west of Betelgeuse in the constellation Orion. The analysis of the calibrated Wing photometry (Wing 1992: JAAVSO 21, 42) returns measures of the temperature (via calibrated Wing TiO- and near-IR (B-C) color-indices) as well as estimates of bolometric magnitude (m-bol). The Wing intermediate band A-filter is used to measure the temperature-sensitive TiO 719-nm (gamma; 0, 0) molecular band. The B (750-nm) and C (1020.4-nm) filters are centered on relatively line-free stellar continuum regions. The C-band filter measures have been calibrated with K-M stars with bolometric magnitudes returning proxy measures of the apparent bolometric magnitude (m-bol) (see Wasatonic et al. 2015: PASP, 127, 1010). During the 25-years of V-band / Wing Near-IR photometry, Betelgeuse is currently the coolest and least luminous yet observed. Since September 2019, the star's temperature has decreased by ~100 K while its luminosity (inferred from the C-band/m-bol observations) has diminished by nearly 25%. At face value using R'/R = [(T'/T)^4 / L'/L]^0.5 (where R', T' and L' are the current values of stellar Radius, Temperature & Luminosity), this implies an increase of the star's radius of ~9%. However, as pointed out by others, the current fainting episode could also arise from expelled, cooling gas/dust partially obscuring the star. The recent changes defined by our V-band/Wing photometry seem best explained from changes in the envelop-outer convection atmosphere of this pulsating, unstable supergiant. If these recent light changes are due to an extra-large amplitude light pulse on the ~420-day period, then the next mid-light minimum is expected during late January/early February, 2020. If Betelgeuse continues to dim after that time then other possibilities will have to be considered. The unusual behavior of Betelgeuse should be closely watched.

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atel_13470

Title: A rapidly growing flare of Cygnus X-3 observed with the Nasu telescope array at 1.4GHz Authors: K. Tsubono (Univ. Tokyo), K. Asuma (Asaka High School), K. Niinuma, T. Aoki (Yamaguchi Univ.), K. Takefuji (JAXA), and T. Daishido (Waseda Univ.) Date: 12 Feb 2020; 14:20 UT Provenance: Kimio Tsubono ([email protected]) Subjects: Radio, Binary, Black Hole, Transient Description: Referred to by ATel #: 13866 Recent quenched/hypersoft state and gamma-ray flare of Cygnus X-3 were reported by AGILE team (ATel #13423, #13458). After that, RATAN 600 reported the beginning of a radio flare from Cygnus X-3 (ATel #13461). With the Nasu telescope array, we have been monitoring Cygnus X-3 daily from last October (drift-scan mode). On February 8 this year, we could observe the appearance of a new activity of Cygnus X-3 with the flux level of 1.48 +/- 0.02 Jy (UT 02:17) at 1.4 GHz. During next four days the observed flux showed rapid increase up to 15.11 +/- 0.02 Jy on February 12 02:01 UT. Ten days light curve including preceding five days data with five-sigma noise level can be shown in the figure below. We will continue our radio monitoring for a while. The Nasu telescope array is a spatial FFT interferometer consisting of linearly aligned eight antennas with 20-m spherical dishes. This type of interferometer was developed to survey transient radio sources with a high angular resolution that of 160-m dish and at the same time with a wide field-of-view that of 20-m dish. 10 days light curve of Cyg X-3 at 1.4GHz

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atel_13530

Title: MAXI/GSC detects renewed activity from MAXI J1820+070 Authors: R. Sasaki (Chuo U.), H. Negoro (Nihon U.), S, Nakahira (JAXA), M. Shidatsu (Ehime U.), M. Nakajima, W. Maruyama, M. Aoki, K. Kobayashi, R. Takagi (Nihon U.), T. Mihara, C. Guo, Y. Zhou, T. Tamagawa, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, H. Nishida, A. Yoshida (AGU), Y. Tsuboi, W. Iwakiri, H. Kawai, T. Sato (Chuo U.), N. Kawai, M. Oeda, K. Shiraishi (Tokyo Tech), Y. Sugawara, S. Ueno, H. Tomida, M. Ishikawa, R. Shimomukai, M. Tominaga (JAXA), Y. Ueda, A. Tanimoto, S. Yamada, S. Ogawa, K. Setoguchi, T. Yoshitake (Kyoto U.), H. Tsunemi, T. Yoneyama, K. Asakura, S. Ide (Osaka U.), M. Yamauchi, S. Iwahori, Y. Kurihara, K. Kurogi, K. Miike (Miyazaki U.), T. Kawamuro (NAOJ), K. Yamaoka (Nagoya U.), Y. Kawakubo (LSU), M. Sugizaki (NAOC) Date: 28 Feb 2020; 01:04 UT Provenance: Satoshi NAKAHIRA ([email protected]) Subjects: X-ray, Binary, Black Hole, Transient Description: Referred to by ATel #: 14492 We report on the detection of the black hole X-ray binary MAXI J1820+070 = ASASSN-18ey (e.g. ATel #11399, #11400) with MAXI/GSC. Following the recent optical rebrightening reported by Adachi et al. (ATel #13502), the MAXI/GSC nova alert system (Negoro et al. 2016) detected an X-ray flux increase of the source at 12:31 UT on 2020 February 27 in the one-day time-bin. The X-ray flux in the 2-10 keV band was 16 ± 3 mCrab (1 sigma error) on February 27. Follow-up observations are encouraged.

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atel_13590

Title: The asteroid (7132) Casulli is a binary system Authors: Lorenzo Franco (A81 - Balzaretto Observatory, Rome - Italy), Alessandro Marchini, Giacomo Bonnoli (K54 - Astronomical Observatory, Department of Physical Sciences, Earth and Environment, University of Siena - Italy), Riccardo Papini (K49 - WBRO Carpione Observatory, San Casciano Val di Pesa, Florence - Italy), Paolo Bacci, Martina Maestripieri (104 - San Marcello Pistoiese Observatory, Pistoia - Italy), Nello Ruocco (C82 - Osservatorio Astronomico Nastro Verde, Sorrento - Italy), Nico Montigiani, Massimiliano Mannucci (A57 - Margherita Hack Observatory, Florence - Italy), Giulio Scarfi (K78 - iota Scorpii Observatory, La Spezia - Italy) Date: 25 Mar 2020; 16:28 UT Provenance: Giacomo Bonnoli ([email protected]) Subjects: Optical, Asteroid, Binary, Planet (minor), Solar System Object, Asteroid (Binary) Description: (7132) Casulli is a main belt asteroid discovered on 1993 Sept. 17 by A. Vagnozzi at Stroncone (Italy) and is named in honor of Silvano Casulli (1944 - 2018), who was the first amateur astronomer in the world to obtain precise astrometric positions of minor planets using a CCD camera (Minor Planet Circular 30800). It orbits with a semi-major axis of about 2.309 AU, eccentricity 0.209, and a period of 3.51 years; it has an absolute magnitude H = 13.6 , a diameter D = 9.015 +/- 0.064 km and a geometric albedo of 0.089 +/- 0.003 (JPL Small-Body Database Browser - ssd.jpl.nasa.gov/sbdb.cgi, 2020; Masiero et al., Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos, Astrophys. J., 791, 2014). Collaborative photometric observations carried out from 2020 February 20 to 2020 March 20 within the Asteroid Research Section of the UAI (Italian Amateur Astronomers Union) reveal that the minor planet (7132) Casulli is a binary system with an orbital period of 36.54 +/- 0.02 h. The rotational light curve of the primary has a period of 3.5238 +/- 0.0002 h with an amplitude of 0.14 mag, suggesting a nearly spheroidal shape. Mutual eclipse/occultation events that are 0.11 to 0.16 mag deep indicate a secondary-to-primary mean-diameter ratio of 0.21 +/- 0.04. Differential photometry measurements and dual-period search were performed using MPO Canopus. The phase plots for the primary (rotational) and secondary (orbital) periods of the system are available at this page: https://www.dsfta.unisi.it/it/notizie/il-telescopio-delluniversita-di-siena-scopre-che-lasteroide-7132-casulli-e-un-sistema Instrumentation used for this campaign is listed below: \- K54 - Astronomical Observatory, DSFTA - University of Siena: 0.30 m f/5.6 MCT, SBIG STL-6303e CCD \- K49 - WBRO Carpione Observatory: 0.23 m SCT f/10 SBIG ST8-XME CCD \- 104 - San Marcello Pistoiese Observatory: 0.60 m f/4 NRT, apogee U6 CCD \- C82 - Osservatorio Astronomico Nastro Verde: 0.35 m f/10 SCT, ST10 CCD \- A57 - Margherita Hack Observatory: SCT 0.35 m, ST10XME CCD \- K78 - iota Scorpii Observatory : 0.40 m f/8 RCT, SBIG STXL-6303E CCD (Telescopes MCT: Maksutov-Cassegrain, NRT: Newtonian Reflector, RCT: Ritchey-Chretien, SCT: Schmidt-Cassegrain). Any enquiry on these observations may be sent to Lorenzo Franco (lor_franco -at- libero.it). Rotational and orbital phase plots for (7132) Casulli

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atel_13650

Title: X-ray pulsations from the recently discovered Be/X-ray binary eRASSU J052914.9-662446 in the LMC Authors: C. Maitra (MPE), F. Haberl (MPE), O. Koenig (ECAP/FAU), V. Doroshenko (IAAT, Tuebingen), S. Carpano (MPE), L. Ducci (IAAT, Tuebingen) Date: 21 Apr 2020; 21:34 UT Provenance: Frank Haberl ([email protected]) Subjects: X-ray, Neutron Star, Star, Pulsar Description: During the beginning of the first all-sky survey (eRASS1), the eROSITA instrument on board the Russian/German Spektrum-Roentgen-Gamma (SRG) mission discovered a new Be/X-ray binary in the Large Magellanic Cloud (LMC) with the classification based on its hard X-ray spectral properties and its spatial coincidence with a Be star (ATel #13610). Following the detection, a NuSTAR observation was performed to further investigate the broad-band X-ray properties of the source. Here we report the discovery of pulsations with a period of ~1412 s in the X-ray flux of eRASSU J052914.9-662446. The NuSTAR observation was performed between 2020-04-08 (MJD 58947.076) and 2020-04-09 (MJD 58948.29) with an effective exposure of 62.7 ks on FPMA and 62.3 ks on FPMB. Strong pulsations are detected independently in the 3.0 -78.0 keV light curves obtained from FPMA and FPMB thereby confirming the source as an X-ray pulsar. The detected spin period is 1412(5) s where the error corresponds to one sigma confidence. The 3.0-50.0 keV spectrum can be described by an absorbed cutoff-powerlaw model with no additional features, a photon index of 1.2(5), a folding energy of 11(7) keV and an absorption column density of 5(4)×1022 H cm-2. The uncertainties in the spectral parameters correspond to 90% confidence. The observed source flux was ~2.4×10-12 erg cm-2 s-1 in the 3.0-78.0 keV band, corresponding to an absorption-corrected luminosity of ~1036 erg s-1, assuming a distance of 50 kpc. The detailed analysis of NuSTAR and eROSITA data will be published elsewhere. We thank the NuSTAR SOC team for the quick scheduling of the DDT observation.

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atel_13710

Title: XB-NEWS detects a new outburst from MAXI J1348-630 Authors: Maria Cristina Baglio, David M. Russell, D. M. Bramich, Payaswini Saikia, Saarah F. Pirbhoy (NYU Abu Dhabi), Fraser Lewis (Faulkes Telescope Project & Astrophysics Research Institute, LJMU) Date: 6 May 2020; 05:32 UT Provenance: Maria Cristina Baglio ([email protected]) Subjects: Optical, X-ray, Binary, Black Hole, Transient Description: Referred to by ATel #: 13994, 14016 The black hole candidate MAXI J1348-630 was discovered by MAXI/GSC on 2019 January 26 (ATel #12425). The discovery outburst lasted until the end of April 2019, when the source entered a quiescent phase (ATel #12441, #12447, #12456, #12469, #12470, #12471, #12477, #12491, #12497). Later on, two reflares were observed (in May and September 2019, respectively; ATel #12829, #12838, #13188), and at the beginning of February 2020 the source started a new re-brightening that was first detected at optical frequencies by our monitoring performed with the Las Cumbres Observatory (LCO) 2-m and 1-m robotic telescopes (ATel #13451), and was then confirmed by MAXI/GSC (ATel #13459). According to NICER observations, MAXI J1348 was in the hard state at the start of this last re-brightening (ATel #13465). We have been closely monitoring the source since the start of its first outburst in January 2019 with LCO. The analysis of the LCO data are performed with a new real-time data analysis pipeline, the ''X-ray Binary New Early Warning System (XB-NEWS; see Russell et al. 2019 and Pirbhoy et al. 2020, ATel #13451 for details). After the detection of the last re-brightening, the source faded again at optical frequencies, going back to the quiescent level that was reached before the start of the re-brightening. In particular, the source magnitude faded from a peak of i'=16.83+/-0.01, g'=18.44+/-0.01 on MJD 58882.0 (February 03) to its faintest magnitude of i'=20.04+/-0.08 on MJD 58935.7 (March 27). Very recently, a new brightening was observed by LCO, with magnitudes going from i'=19.93+/-0.03 on MJD 58961.5 (April 22) to i'=16.98+/-0.01 on MJD 58973.3 (May 4). The most recent magnitudes (MJD 58973.7, May 4) show that the brightening is still ongoing, with i'=16.91+/-0.01, r'=17.47+/-0.01, g'=18.46+/-0.02. The brightening has probably not reached its peak yet. We noticed that a slight X-ray brightening is observed in both the MAXI and Swift/BAT monitoring at the same time as the optical one. However, more observations are necessary in order to confirm this. The optical monitoring of the source with LCO is still ongoing. Further multiwavelength observations are therefore encouraged in order to confirm the brightening and determine the accretion state of the source. The LCO observations are part of an on-going monitoring campaign of ~ 40 low-mass X-ray binaries (Lewis et al. 2008) with LCO and the Faulkes Telescopes. This work makes use of observations from the Las Cumbres Observatory (LCO). We acknowledge the support of the NYU Abu Dhabi Research Enhancement Fund under grant RE124. Optical LCO light curves of MAXI J1348-630

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atel_13775

Title: MASTER: optical activity of flaring FSRQ PMN J1903- 6749 Authors: V. Lipunov, K. Zhirkov, O. Gress, K. Zhirkov, V. Kornilov, E. Gorbovskoy, A. Chasovnikov, N. Tiurina, P. Balanutsa, I. Gorbunov, A. Kuznetsov, V. Vladimirov, D. Vlasenko, F. Balakin, D. Zimnukhov, D. Cheryasov, V. Senik, E. Minkina, V. Grinshpun, V. Shumkov, T. Pogrosheva, V. Topolev, A. Pozdnyakov (Lomonosov MSU), D. A. H. Buckley (SAAO), R. Podesta, F. Podesta, C. Francile (OAFA), H. Levato (SJNU), N. M. Budnev(ISU, API), A. Gabovich, Yu. Sergienko(BSPU), R. Rebolo, M. Serra-Riscart, (IAC), A. Tlatov, D. Dormidontov(Kislovodsk Solar Station of the Pulkovo Observatory) Date: 2 Jun 2020; 19:37 UT Provenance: Nataly Tyurina ([email protected]) Subjects: Optical, Gamma Ray, AGN, Blazar, Quasar Description: MASTER-NET reports on enhanced optical activity of the flaring FSRQ PMN J1903- 6749 as reported by the Fermi-LAT Collaboration (Angioni et al. ATEL #13767). MASTER-OAFA and MASTER-SAAO observed this object at the beginning and the end of the day of the gamma-ray flare. We obtain three frames on which the object is clearly visible, although the second one has heavily distorted objects. Date | Time UTC | magnitude | Filter | Facility 2020-05-27 | 00:55:44 | 16.03 | C | MASTER-OAFA 2020-05-27 | 20:36:15 | 15.41 | C | MASTER-SAAO 2020-05-28 | 03:31:24 | 14.38 | C | MASTER-OAFA We used GAIA catalog for flux calibration. We conclude that during the gamma-ray flare object experienced an optical flare with an amplitude of at least 1.6 magnitude. We encourage further multi-wavelength support of this object. MASTER Global Robotic Net

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atel_13875

Title: New Enhanced Activity of Mrk 421 measured by HAWC Authors: Jose Andres Garcia-Gonzalez (IF-UNAM, jagarcia@fisica. unam. mx, ITESM-EIC, anteus79@tec. mx), Israel Martinez (UMD, imc@umd. edu) on behalf of the HAWC Collaboration Date: 18 Jul 2020; 03:52 UT Provenance: José Andrés García-González ([email protected]) Subjects: Gamma Ray, TeV, AGN, Blazar Description: In the past night the HAWC gamma-ray observatory has observed an increased TeV gamma-ray emission from Markarian 421, with a flux above 1 TeV of (8.91 +/- 1.10) X 10^-11 cm^-2s^-1 (~ 5 equivalent Crab units) between 2020-07-17 8:42:07 and 2020-07-18 00:58:05 UTC. This new increase in the integrated flux has been preceded for an extended period of high activity that lasted from Jun 14th to Jun 21th (see for ref. #Atel 13808, #Atel 13831). HAWC continuously monitors this source and will keep reporting in case that the enhance activity follows. Follow-up observations are encouraged. All flux values are obtained from a maximum likelihood fit under the assumption of a fixed spectral shape with power law index of 2.2 and exponential cut-off at 5 TeV. The HAWC contact people for this analysis are Jose Andres Garcia-Gonzalez (IF-UNAM, [email protected], ITESM-EIC, [email protected]) and Israel Martinez (UMD, [email protected]). HAWC is a TeV gamma ray water Cherenkov array located in the state of Puebla, Mexico, that monitors two thirds of the sky every day with an instantaneous field of view of ~2 sr.

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atel_13950

Title: Radio observations of the magnetar AX J1846.4-0258 Authors: Mitchell B Mickaliger (University of Manchester), Kaustubh Rajwade (University of Manchester), Benjamin Stappers (University of Manchester), Andrew Lyne (University of Manchester), Lina Levin Preston (University of Manchester) Date: 17 Aug 2020; 15:10 UT Provenance: Mitchell Mickaliger ([email protected]) Subjects: Radio, Magnetar Description: Referred to by ATel #: 13988 Following the detection of an X-ray flare from the magnetar AX J1846.4-0258 by Swift (ATel #13913) and MAXI/GSC (ATel #13922), we performed follow-up radio observations with the 32-m Mk2 telescope at Jodrell Bank Observatory. We observed the source on 2020-08-05 (MJD 59066) at 17:37:00 UT for 4189 seconds, 2020-08-12 (MJD 59073) at 00:56:33 UT for 2919 seconds, 2020-08-13 (MJD 59074) at 19:40:16 UT for 1969 seconds, and 2020-08-14 (MJD 59075) at 00:39:43 UT for 3330 seconds. These data were recorded using a DFB backend (Manchester et al., 2013), and were coherently dedispersed and folded. All observations were centered at a frequency of 1532 MHz, with a bandwidth of 384 MHz over 32 channels. No detections were made in these four observations. The nominal DM of the source (300 pc cm^-3) agrees with the accepted distance to the source, 5.5--5.9 kpc (Verbiest et al., 2012), based on the NE2001 Galactic free-electron density model (Cordes & Lazio, 2002). Assuming roughly a factor-of-two error on the distance, and using the upper limit from Leahy & Tian (2008) of 13.2 kpc, gives a maximum DM of 1175 pc cm^-3. A further search using 'pdmp,' which is part of the PSRCHIVE software suite (van Straten et al., 2011), was performed around the nominal period (326.6 ms), but did not reveal any radio emission. We then ran a wider search over a DM range of 0--1175 pc cm^-3 and no pulsations were detected. Assuming a duty cycle of 50%, a sky temperature of 10 K, and an effective bandwidth of 250 MHz, the 1-sigma upper limits on the radio flux of this source during these four observations are 86 uJy, 103 uJy, 126 uJy, and 97 uJy, respectively. We plan to continue radio observations of this source.

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atel_14070

Title: Latest increased Activity of Mrk 421 measured by HAWC Authors: Jose Andres Garcia-Gonzalez (IF-UNAM, jagarcia@fisica. unam. mx, ITESM-EIC, anteus79@tec. mx), Israel Martinez (UMD, imc@umd. edu) on behalf of the HAWC Collaboration Date: 7 Oct 2020; 15:31 UT Provenance: José Andrés García-González ([email protected]) Subjects: Gamma Ray, TeV, AGN, Blazar Description: In the past day the HAWC gamma-ray observatory has observed an increased TeV gamma-ray emission from Markarian 421, with a highest flux above 1 TeV of (11.01 +/- 1.64) X 10^-11 cm^-2s^-1 ( 6.22 equivalent Crab units) from 2020-10-06 13:23:39 to 2020-10-06 16:31:38 UTC. This new increase in the integrated flux has been preceded by an extended period of high activity with some interruptions (see for ref. #Atel 13808, #Atel 13831, #Atel 13875, #Atel 13917 and #Atel 13993). The summary of this new activity period is as follows: Duration of a full transit is 6.2 hr, we are separating the transit in two parts of ~ 3.1 hr each: MJD 59128 (2020-10-06 13:23:39 - 2020-10-06 16:31:38 UTC) (rising) Preliminary flux level: 11.01 +/- 1.64 X 10^-11 cm^-2s^-1 [>1 TeV] (6.22 CU) MJD 59128 (2020-10-06 16:31:38 - 2020-10-06 19:39:37 UTC) (setting) Preliminary flux level: 9.49 +/- 1.59 X 10^-11 cm^-2s^-1 [>1 TeV] (5.36 CU) HAWC continuously monitors this source and will keep reporting in case that the enhanced activity follows. Follow-up observations are encouraged. All flux values are obtained from a maximum likelihood fit under the assumption of a fixed spectral shape with power law index of 2.2 and exponential cut-off at 5 TeV. The HAWC contact people for this analysis are Jose Andres Garcia-Gonzalez (IF-UNAM, [email protected], ITESM-EIC, [email protected]) and Israel Martinez (UMD, [email protected]). HAWC is a TeV gamma-ray water Cherenkov array located in the state of Puebla, Mexico, that monitors two thirds of the sky every day with an instantaneous field of view of ~2 sr.

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atel_14175

Title: Spectroscopic Classification of AT 2020zoq as a Young Type II Supernova with the Xinglong 2.16-m Telescope Authors: Shengyu Yan (THU), Zhihao Chen (THU), Xiaofeng Wang (THU), and Jujia Zhang (YNAO) on behalf of a large collaboration Date: 15 Nov 2020; 08:39 UT Provenance: Xiaofeng Wang ([email protected]) Subjects: Optical, Supernovae, Transient Description: We obtained an optical spectrum (range 385-880 nm) of the transient AT 2020zoq(=ASASSN-20oc), discovered by the ASASSN (All-Sky Automated Survey for Supernovae), on UT 2020 Nov.14 21:21:06.00 with the Xinglong 2.16-m telescope (+BFOSC) of NAOC. The spectrum is characterized by blue featureless continuum, with prominent absorption at around 4400 Angstrom. Based on the spectral classification tool GELATO (Harutyunyan et al. 2008, A&A, 488, 383), the spectrum of SN 2020zoq is found to match that of type IIP SN 1999gi at t=+3.8 day after explosion. From the narrow emission line of Ha in the spectrum, a redshift of z=0.01004 can be deduced for the host galaxy UGC 05760.

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atel_14300

Title: Spectroscopic classification of SN 2021J with Faulkes Telescope North/FLOYDS Authors: M. R. Siebert, R. J. Foley (UC Santa Cruz) Date: 4 Jan 2021; 17:50 UT Provenance: Ryan Foley ([email protected]) Subjects: Optical, Supernovae Description: Referred to by ATel #: 14325 We report the classification of SN 2021J with the FLOYDS spectrograph on the 2-m Faulkes Telescope North on UT 2021 Jan 4. The target was supplied by ALeRCE using the ZTF data stream. The classification was performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes ZTF21aaabvit | AT2021J | 12:26:27.03 | +31:13:20.59 | 0.0024 | Ia | -14 d | (1) Notes: When the redshift is given to 2 decimal places, it is derived from the SN spectrum. Otherwise, the redshift is determined from the host galaxy. (1) The spectrum has some host-galaxy contamination, but still has distinct supernova features. In particular, we identify Si II 6355 with a minimum blueshifted by -16,300 km/s. The spectrum is consistent with some very young SNe Ia (e.g., SN 2002bo at -14 days), although with some color mismatch. The continuum is relatively flat (in f_lambda) from 4000-10,000 A, slightly increasing to the blue. There is no obvious Na D absorption in the spectrum, although narrow H alpha and Ca H&K absorption, presumably from the host galaxy, are present. There is therefore no obvious dust extinction from indirect indicators. Assuming a Cepheid distance to NGC 4414 (also the host to SN Ia 1974G and SN IIb 2013df), mu = 31.1 mag (Freedman et al., 2001, ApJ, 553, 47), and Milky Way reddening of A_g = 0.064 mag (Schlafly & Finkbeiner, 2011, ApJ, 737, 103), the current brightness (g = 16.1 mag) corresponds to an absolute magnitude of M_g = -15.1 mag. This luminosity is consistent with a young Type Ia supernova.

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atel_14375

Title: Swift detects X-rays from XTE J1859+226; continued optical brightening. Authors: Eric C. Bellm (UW) Date: 7 Feb 2021; 02:13 UT Provenance: Eric Bellm ([email protected]) Subjects: Optical, X-ray, Binary, Black Hole Description: Referred to by ATel #: 14415, 14512 We analyzed 1.4 ksec of PC-mode Swift-XRT quicklook data for the black hole LMXB XTE J1859+226, which has brightened in the optical (ATel #14372). We detect a single source at 18h58m41.25s +22d39m35.5s in the 0.3-10 keV band, which we identify as XTE J1859+226. The spectrum is well-fit by an absorbed power law with photon index 1.7+/-0.4 and an observed 0.3-10 keV flux of 7.9 (+2.0, -1.5) x 10-12 erg cm-2 s-1. This represents a substantial brightening relative to the quiescent 0.3-8 keV flux of 1.5 x 10-15 erg cm-2 s-1 reported by Tomsick et al. (2003). Zwicky Transient Facility observations on UTC 2021-02-06.6 indicate that the source continues to brighten in the the optical, with the flux increasing by ~0.4 mag in the past two days (see https://antares.noirlab.edu/loci/ANT2021dn4jk). We conclude that XTE J1859+226 is in the early stages of an outburst; multiwavelength observations are encouraged. Based on observations obtained with the Samuel Oschin Telescope 48-inch and the 60-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-2034437 and a collaboration including Caltech, IPAC, the Weizmann Institute for Science, the Oskar Klein Center at Stockholm University, the University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, the TANGO Consortium of Taiwan, the University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, and IN2P3, France. Operations are conducted by COO, IPAC, and UW. We acknowledge further support from the NSF under grants AST-1812779 and the Heising-Simons Foundation under grant 2018-0908.

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atel_14490

Title: NICER X-ray activity shows GX 339-4 undergoing a rapid state transition Authors: Jingyi Wang (MIT), James F. Steiner (SAO, CfA), Erin Kara (MIT), Andy Fabian (University of Cambridge), Keith Gendreau, Zaven Arzoumanian (NASA/GSFC), Jeroen Homan (Eureka Scientific/SRON), Javier Garcia (Caltech), Phil Uttley (University of Amsterdam), Tomaso Belloni (INAF-OAB), John Tomsick (UC Berkeley), Poshak Gandhi (Southampton) for the NICER team Date: 28 Mar 2021; 14:22 UT Provenance: Jingyi Wang ([email protected]) Subjects: X-ray, Black Hole, Transient Description: Referred to by ATel #: 14493, 14494, 14507, 14953, 15615 GX 339-4 is a black hole X-ray binary that started a new outburst in the last week of January 2021 (ATel #14351, #14367, #14352, #14354). After that, the source slowly brightened for 2 months while remaining in the hard state, as suggested by X-ray spectral and timing properties (ATel # 14384, #14400, #14440, #14455, #14484), and optical monitoring (ATel #14419). NICER observed GX 339-4 with a near-daily cadence from 2021-01-20 (MJD 59234) to 2021-03-20 (MJD 59293), by which time it reached a mean NICER count rate of ~1,200 counts/s/52 FPMs, and a model-determined absorbed flux in 0.5-10 keV of 4.5E-9 erg cm-2 s-1 (0.15 Crab) using the model Tbabs\\*(simplcut\\*diskbb+laor). The fitted column density, using Wilms et al. 2000 abundances, is (5.77+/-0.02)E21 cm-2. The disk temperature was ~0.3 keV with a thermal flux - to - bolometric fraction of 0.14, and a photon index of ~1.74, confirming the source was still in a bright hard state. After a 6-day visibility gap, NICER monitoring resumed. From the first of these observations on 2021-03-26 (MJD 59299) to 2021-03-28 (MJD 59301.42), the count rate exhibited a dramatic increase at ~2,500 counts/s/52 FPMs, and rose rapidly reaching ~4,600 counts/s/52 FPMs. With the same model, we found the associated increase in the modeled absorbed flux (7.9E-9 to 1.1E-8 erg cm-2 s-1, i.e., 0.26 to 0.36 Crab), the disk temperature (0.46 to 0.61 keV), the disk flux fraction (0.40 to 0.63), and also the photon index (~2.22 to ~2.79). The dramatic evolution of these spectral parameters all suggest that GX 339-4 has gone into the hard intermediate state and is evolving rapidly towards the soft-intermediate/soft state. From the power spectra, we also see an evolution in the QPO frequencies and the variability level. Before the visibility gap, the integrated 0.1-64 Hz fractional rms in 0.4- 10 keV was 27% , and a strong QPO at 0.51 Hz ( rms 9%) was present. After the coverage gap, the total fractional rms dropped from 11% to 6%; the QPO moved to higher frequencies (~2.58 Hz to ~5.29 Hz) with lower rms (4.0% to 2.1%). The QPO became more prominent and narrower until MJD 59300.8 (Q factor 8 to 9), and became weaker and blunter at MJD 59301.4 (Q factor of 3). In 4-10 keV, the integrated 0.1-64 Hz fractional rms was 31% before the gap, and dropped slightly from 21% to 18% after the gap. These changes also indicate that the source entered the hard-to-soft state transition during the gap in visibility. NICER will continue to observe nearly every ~90 minutes for the next couple of weeks, unless we determine it is not worth covering at this cadence. We encourage further multi-wavelength observations as the source has entered a hard-to-soft state transition and is approaching the soft intermediate state, where both QPO type transitions and transient ballistic jets are commonly observed. NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA. The hardness-intensity diagram, power spectra, and parameter evolution.

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atel_14575

Title: Spectroscopic Confirmation of ASASSN-21gq = AT 2021klf = ZTF21aanfcmk as a gravitational micro-lensing event Authors: Kenta Taguchi, Keisuke Isogai, Naoto Kojiguchi, Yusuke Tampo(Kyoto University) Date: 26 Apr 2021; 07:47 UT Provenance: Keisuke Isogai ([email protected]) Subjects: Optical, Microlensing Event, Transient, Variables Description: We report our spectra of the transient ASASSN-21gq = AT 2021klf = ZTF21aanfcmk. We obtained the spectra from 2021-04-25.773 UT to 2021-04-25.788 UT using the fiber-fed integral field spectrograph (KOOLS-IFU; Matsubayashi et al. 2019) mounted on the 3.8-m Seimei telescope (Kurita et al. 2020) at Okayama Observatory of Kyoto University. As reported to TNS, this object is discovered by ASAS-SN at g = 15.4 AB mag on 2021-04-24.260. There is a PS1 counterpart of g = 18.50, r = 17.77, i = 17.42, z = 17.24, and y = 17.07. Before the discovery by ASAS-SN, ZTF detected it at r ∼ 17.26 on 2021-02-24.54. After one month, ZTF detected it again at r = 16.80 on 2021-03-27.465 and g = 17.70 on 2021-03-27.503. Then, this object has been gradually rising for 2.5 mag, during which the g - r color remained almost constant (the last record of ZTF is r = 14.34 on 2021-04-24.416 and g = 15.18 on 2021-04-24.482). Our spectra show a red continuum and Balmer (Hα and Hβ), the infrared Ca II triplet, Na I D, CH, and Fe I absorption lines. Such spectral features are consistent with a normal G-type star. The g - r color is also consistent with a normal G-type star. Based on our spectra, the almost-constant g - r color, and the profile of the light curve, we conclude that this object is a high-amplitude gravitational microlensing event. If you want to contact us, please send an e-mail to [email protected]. Our Spectrum

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atel_14625

Title: VVV near-IR observations of V6585 Sgr progenitor Authors: T. S. Ferreira, R. K. Saito (Universidade Federal de Santa Catarina), D. Minniti (Universidad Andres Bello, Vatican Observatory) Date: 14 May 2021; 13:38 UT Provenance: Roberto Saito ([email protected]) Subjects: Infra-Red, Nova Description: Referred to by ATel #: 14655 Following the spectroscopic follow-up observations of V6585 Sgr (a.k.a. PNV J17581670-2914490) by Taguchi et al. (2021, ATels #14513/#14514) and Bayless et al. (2021, ATel #14553) and later Swift observations by Sokolovsky et al. (2021, ATel #14535), we explored archival near-IR (NIR) images from the VVV Survey (vvvsurvey.org; Minniti et al. 2010, New Astron., 15, 433) of the Galactic bulge within the area containing the reported object. A single source with flag "-1", indicating a stellar source in all five ZYJHKs NIR bands, was detected within 2 arcsecond radius from the target position as reported by Taguchi et al. (2021, ATel #14513), at coordinates: RA (J2000): +269.5702134 Dec (J2000): -29.2469424 and presenting the following NIR magnitudes (yyyy-mm-dd): Z: 16.44+/-0.07 (2010-08-30) Y: 15.97+/-0.08 (2010-08-30) J: 15.24+/-0.06 (2011-05-09) H: 14.40+/-0.05 (2011-05-09) Ks: 14.11+/-0.05 (2012-03-26) Moreover, we searched for variability in the NIR data of V6595 Sgr progenitor making use of the Lomb-Scargle (LS; Lomb 1976, Ap&SS 39; Scargle 1982, ApJ 1:263) and the Phase Dispersion Minimisation methods (PDM, Stellingwerf 1978, Astrophysical. J. v224) across 101 VVV-DR4 Ks-band epochs over three years of observations, from September 2010 to September 2013. The object shows a low significance, likely periodic signal of period P_LS = 0.2841 days and P_PDM = 0.2920 days, with an amplitude of Delta_Ks ~ 0.2 mag in both methods.

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atel_14675

Title: Swift J1555.2-5402: Swift XRT refined analysis of the new SGR Authors: P. A. Evans (U. Leicester) Date: 3 Jun 2021; 19:55 UT Provenance: Phil Evans ([email protected]) Subjects: X-ray, Neutron Star, Transient, Magnetar Description: Referred to by ATel #: 14679 We have analysed further Swift-XRT data on the new SGR, Swift J1555.2-5402 (GCN Circs 30120, 30121; ATEL #14674). Note that the name stated in GCN 30120 and subsequent publications was incorrect: the object name is Swift J1555.2-5402. The XRT has observed the SGR from T0+100 s to T0+5715 s, gathering 62 s of data in Windowed Timing mode and 1.7 ks in Photon Counting mode. As reported by Coti Zelati et al., (GCN Circ. 30121), our data show an X-ray source, for which we find an enhanced position of RA,Dec = 238.78608, -54.06142, which is equivalent to: RA (J2000.0) = 15h 55m 08.66s Dec (J2000.0) = -54d 03' 41.1" with an uncertainty of 2.2" (radius, 90% confidence). A spectrum formed from the PC mode data can be well fit with a highly absorbed power-law with a photon index of 2.3 (+1.0, -0.9) and an absorption column of 1.2 (+0.5, -0.4) × 1023 cm-2. The light curve currently shows an approximately constant count-rate of one count per second. This ATEL is an official product of the Swift team.

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atel_14775

Title: The quasar TON 0599 reaches a new optical maximum Authors: Adrian Scherbantin, Lukas Kunkel, Karl Mannheim (all Universitaet Wuerzburg), Niels Bader, Erik Heidemann, Karim Heidemann, Felix Hemrich, Ben Horst, Kai Koeberlein, Felix Molz, David Reinhart, Korbinian Rosenlehner, Kilian Schoch, Remco Steineke, Dirk Seifert, Lukas Waller, Nils Zottmann, Martin Feige, Christian Lorey (all Friedrich-Koenig-Gymnasium / Hans-Haffner-Sternwarte), Dominik Elsaesser (TU Dortmund) Date: 12 Jul 2021; 16:55 UT Provenance: Dominik Elsaesser ([email protected]) Subjects: Optical, AGN, Quasar Description: Referred to by ATel #: 14781, 14785, 15441, 15870 Since January of this year, the flat-spectrum radio quasar Ton 0599 (4C 29.45, PKS 1156+295; ICRS coords. (ep=J2000): RA 11 59 31.834 Dec +29 14 43.827 z=0.7) has been showing strong activity in both the optical (ATel # 14353; # 14391; # 14547; # 14696) and gamma-ray (ATel # 14722) spectral regions. After a high magnitude of 13.91 on April 10, 2021 (JD = 2459314.4999), a very high magnitude in the R band of 13.70 was published for June 17, 2021 (ATel # 14727). Last night (JD 2459407.4356) we were now able to measure a value of 13.516 (+/-0.007) in R-band, which is quite exceptional for this object. After flares in mid-April 2012 (ATel # 4051) and early May 2015 (ATel # 7474), each with a brightness of 15.1 mag, and of 14.22 (ATel # 10948) and 14.03 (ATel # 10949) in November 2017, the highest brightness to date of 15 to 13 mag (R-band, fractional magnitude values not specified) was then reached in May 2018 (ATel # 11624). Due to the weather situation, we will probably not be able to continue monitoring this object during the next nights. So we propose a further observation by other observatories. Here are the values of the last nights of TON 0599: R - band magnitudes: JD 2459367.4690: 15.806 ± 0.010 JD 2459377.4543: 14.753 ± 0.009 JD 2459378.4309: 14.697 ± 0.014 JD 2459383.4228: 14.013 ± 0.008 JD 2459401.4435: 13.692 ± 0.006 JD 2459403.4059: 13.718 ± 0.005 JD 2459406.3712: 13.872 ± 0.020 JD 2459407.4356: 13.516 ± 0.007 V - band magnitudes: JD 2459367.4735: 16.301 ± 0.014 JD 2459377.4589: 15.192 ± 0.013 JD 2459378.4356: 15.163 ± 0.016 JD 2459383.4183: 14.439 ± 0.009 JD 2459401.4481: 14.087 ± 0.007 JD 2459403.4105: 14.106 ± 0.006 JD 2459406.3758: 14.304 ± 0.014 JD 2459407.4402: 13.937 ± 0.009 B - band magnitudes: JD 2459367.4781: 16.865 ± 0.019 JD 2459377.4636: 15.776 ± 0.023 JD 2459378.4403: 15.681 ± 0.020 JD 2459383.4137: 14.925 ± 0.014 JD 2459401.4527: 14.650 ± 0.012 JD 2459403.4150: 14.635 ± 0.010 JD 2459406.3804: 14.800 ± 0.057 JD 2459407.4450: 14.503 ± 0.015 These measurements were carried out as part of the long-term AGN monitoring program of the Naturwissenschaftliches Labor fuer Schueler am Friedrich-Koenig-Gymnasium (FKG), the Universitaet Wuerzburg, and the TU Dortmund University with the 0.5m CDK astrograph at the school and university observatory Hans-Haffner-Sternwarte in D-97265 Hettstadt (Germany). Monitoring Programm Website

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atel_14850

Title: NICER X-ray observations of the recurrent nova RS Ophiuchi Authors: Teruaki Enoto (RIKEN), Hiroyuki Maehara (National Astronomical Observatory of Japan), Marina Orio (University of Wisconsin and INAF-Padova), Andrew Fabian (IoA, Cambridge), Michael Parker (IoA, Cambridge), Keith Gendreau (NASA/GSFC), Zaven Arzoumanian (NASA/GSFC), Pragati Pradhan (MIT Kavli Institute for Astrophysics and Space Research), Elizabeth C. Ferrara (University of Maryland, CRESST, NASA/GSFC), Jon M. Miller (Univ. of Michigan) Date: 11 Aug 2021; 20:52 UT Provenance: Teruaki Enoto ([email protected]) Subjects: X-ray, Nova Description: Referred to by ATel #: 14855, 14857, 14858, 14860, 14864, 14882, 14885, 14886, 14894, 14895 A new outburst of the recurrent nova RS Opiuchi (RS Oph) was reported on 2021 August 8 (ATels #14834, #14838, #14840, #14846), 15 years after the last outburst in 2006 (ATel #737). The Neutron Star Interior Composition Explorer (NICER) observed RS Oph on 2021 August 10, from 11:57:00 to 12:14:20 UTC, with an exposure of 942 sec. This observation was coordinated simultaneously with optical monitoring of the 3.8-meter SEIMEI Telescope to study the maximum of the optical light curve. During the NICER observation, the 1-10 keV count rate was stable at around 55 cts/s. The X-ray spectrum can be approximated with a model of collisionally ionized gas with a temperature of ~5 keV and the absorption column density of ~6e+22 cm-2 (implying large intrinsic absorption in addition to the interstellar value of about 2.0E+21 cm-2). A prominent iron emission line was observed at 6.7 keV, along with several other possibly unresolved Sulphur lines in the soft X-ray band around 2.5 keV. The absorbed 1-10 keV flux was 5e-10 erg/s/cm2. Two NICER observations taken 17 hours later showed a slightly lower absorption (~3e+22) and an increase in flux especially below 2 keV, reaching ~ 7e-10 erg/s/cm2 in the 1-10 keV band with ~ 68 cts/s. Preliminary spectral modeling suggests that the velocity of the shock-heated ejecta evolved from 3100 km/s to 1050 km/s between the first two observations, further slowing down to 980 km/s in the third observation. NICER is a 0.2-12 keV X-ray telescope operating on the International Space Station. The NICER mission and portions of the NICER science team activities are funded by NASA. We are planning to continue NICER observations of RS Oph. NICER observations planned for RS Oph and other targets can be found at https://heasarcdev.gsfc.nasa.gov/docs/nicer/schedule/nicer_sts_current.html.

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atel_14940

Title: Apparent Outburst of Comet 382P/Larson Authors: Michael S. P. Kelley (U. Maryland), Tim Lister (Las Cumbres Observatory), Kritti Sharma (IITB), Vishwajeet Swain (IITB), Harsh Kumar (IITB), Varun Bhalerao (IITB), G. C. Anupama (IIA), Sudhanshu Barway (IIA) on behalf of the Zwicky Transient Facility Collaboration, the LCO Outbursting Objects Key Project, and GROWTH India Collaboration Date: 28 Sep 2021; 20:51 UT Provenance: Tim Lister ([email protected]) Subjects: Optical, Comet Description: We report an apparent outburst of comet 382P/Larson, discovered in Zwicky Transient Facility (ZTF; Bellm et al. 2019, PASP, 131, a8002) data. Photometry of the comet in the r-band was 18.76+/-0.12, 19.17+/-0.22, and 18.74+/-0.15 at 2021 Sep 16 06:04, Sep 20 05:35, and Sep 22 05:58 UTC, respectively (all photometry is measured with 5" radius apertures and calibrated to the PS1 photometric system). On Sep 27 05:26 UTC, the comet brightened to r=17.84+/-0.03 mag. Comparison to an average of the three previous measurements suggests an outburst strength of -0.98+/-0.09 mag. The outburst was confirmed in subsequent observations with the 0.7-m GROWTH India Telescope on Sep 27 15:48 UTC (r=17.96+/0.03 mag, g=18.62+/-0.05 mag) and a Las Cumbres Observatory 1-m telescope at Cerro Tololo Interamerican Observatory on Sep 27 23:50 (r=17.87+/-0.02 mag). At the time of the outburst discovery, the comet was 4.48 au from the Sun and 3.72 au from the Earth. The comet's next perihelion occurs in March 2022. Based on observations obtained with the Samuel Oschin Telescope 48-inch Telescope at the Palomar Observatory as part of the Zwicky Transient Facility project. ZTF is supported by the National Science Foundation under Grant No. AST-2034437 and a collaboration including Caltech, IPAC, Weizmann Institute for Science, Oskar Klein Center at Stockholm University, University of Maryland, Deutsches Elektronen-Synchrotron and Humboldt University, TANGO Consortium of Taiwan, University of Wisconsin at Milwaukee, Trinity College Dublin, Lawrence Livermore National Laboratories, and IN2P3, France. Operations are conducted by COO, IPAC, and UW. This work makes use of observations from the Las Cumbres Observatory global telescope network. The GROWTH India Telescope (GIT) is a 70-cm telescope with a 0.7 degree field of view, set up by the Indian Institute of Astrophysics (IIA) and the Indian Institute of Technology Bombay (IITB) with funding from DST-SERB and IUSSTF. It is located at the Indian Astronomical Observatory (Hanle), operated by IIA. We acknowledge funding by the IITB alumni batch of 1994, which partially supports operations of the telescope. Telescope technical details are available at https://sites.google.com/view/growthindia/

A

atel_15025

Title: Spectroscopic classification of SN 2021adgz with Gemini-North/GMOS Authors: M. R. Siebert, R. J. Foley (UC Santa Cruz), Qinan Wang (JHU) Date: 8 Nov 2021; 21:59 UT Provenance: Matthew Siebert ([email protected]) Subjects: Optical, Supernovae, Transient Description: We report the classification of SN 2021adgz with the GMOS spectrograph on the Gemini-North Telescope with GMOS on UT 2021 Nov 5. The target was supplied by ALeRCE using the ZTF data stream. The classification was performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes ZTF21acliqdq | AT2021adgz | 11:03:13.11 | +11:04:15.93 | 0.02138 | II | peak | (1) Notes: When the redshift is given to 2 decimal places, it is derived from the SN spectrum. Otherwise, the redshift is determined from the host galaxy. (1) We measure an H-alpha absorption velocity of -10,800 km/s

A

atel_15150

Title: Bright radio emission from Nova Cassiopeiae 2021 = V1405 Cas Authors: Kirill Sokolovsky, Elias Aydi, Laura Chomiuk, Adam Kawash, Jay Strader (MSU), Aliya-Nur Babul, Jennifer Sokoloski (Columbia), Amy Mioduszewski, Justin Linford (NRAO), Koji Mukai (NASA/GSFC), Kwan-Lok Li (NCKU), Tim O'Brien (JBCA/Manchester), Michael Rupen (NRC) Date: 2 Jan 2022; 05:45 UT Provenance: Kirill Sokolovsky ([email protected]) Subjects: Radio, Millimeter, Nova Description: Referred to by ATel #: 15518 The classical nova V1405 Cas was discovered on 2021-03-18.4236 UT by Y. Nakamura (CBET #4945, ATel #14471, #14472, #14476, #14478, #14482, #14530, #14577, #14614, #14620, #14622, #14665, #14704, #14794). For seven month V1405 Cas stayed near its peak optical brightness showing a series of flares with the brightest one reaching V=5.1 according to the AAVSO photometry. Around 2021-11-01 the nova started a steady decline (ATel #15093) and on 2021-12-14 was detected as a super-soft X-ray source (ATel #15111). We follow V1405 Cas with the Karl G. Jansky Very Large Array (VLA) from 2021-06-10 (ATel #14731), prompted by the GeV detection of the nova (ATel #14658). V1405 Cas displays an inverted radio spectrum with flux densities gradually increasing with time at all frequencies, reaching at our latest observing epoch 2021-12-20: # f(GHz) F(mJy) eF(mJy) 2.6 1.110 0.037 3.4 1.679 0.023 5.1 3.333 0.019 7.0 6.356 0.019 13.7 23.685 0.043 16.5 32.958 0.043 31.1 105.930 0.120 34.9 128.630 0.130 A power law fit results in a positively defined spectral index of 1.86 +/-0.02. The source is resolved at 31.1 and 34.9 GHz according to the SNR-adjusted resolution criterion of Kovalev et al. (2005, AJ, 130, 2473) having a Gaussian FWHM size of ~0.07 arcsec. The flux densities above 10 GHz were measured by fitting a circular Gaussian (at 31.1 and 34.9 GHz) or point source model to the uv-data and applying phase-only self-calibration. No self-calibration was applied at lower frequencies (due to more stable phases, fainter target and the presence of other sources within the field of view) - the flux densities were obtained from peaks of naturally-weighted CLEAN images of the nova. We used 3C147 to set the absolute flux density scale (Perley & Butler, 2017, ApJS, 230, 7) with expected uncertainties of 15% at 35 GHz and 5% at lower frequencies. The source J2339+6010 (TXS 2336+598) was used as the phase calibrator. From the 31.1 and 34.9 GHz data we measure the position of the radio emission peak (relative to the phase calibrator) at 23:24:47.7325 +61:11:14.599 J2000. The expected uncertainty is about 0.010 arcsec dominated by the phase calibration errors. The measured flux densities make V1405 Cas one of the brightest radio novae. Among the classical novae well observed in radio only V5668 Sgr (2015), V1369 Cen (2013), V1974 Cyg (1992) and QU Vul (1984) (Chomiuk et al., 2021, ApJS, 257, 49) as well as V959 Mon (2012) (Chomiuk et al. 2014, Nature, 514, 339) reached 100 mJy above 20 GHz (all having inverted spectra). The red giant donor recurrent nova RS Oph reached ~90 mJy at both high and low frequencies during its 2021 eruption (ATel #14886), while another embedded nova V407 Cyg peaked at lower flux densities (Chomiuk et al. 2012, ApJ, 761, 173). The VLA radio spectrum of V1405_Cas on 2021-12-20.

A

atel_15240

Title: The brighter phase of Betelgeuse since 2017 Authors: Costantino Sigismondi (ICRA/Sapienza University of Rome and ITIS G. Ferraris, Rome), Wolfgang Vollmann (AAVSO/BAV), Fabio Mariuzza, Rod Stubbings (AAVSO), Otmar Nickel (University of Mainz and AAVSO/BAV), Sandip V. George (University of Groningen) and Remo Ruffini (ICRANet Pescara) Date: 25 Feb 2022; 00:32 UT Provenance: Costantino Sigismondi ([email protected]) Subjects: Optical, Request for Observations, A Comment, Star, Variables Description: Referred to by ATel #: 16001, 16374 The great dimming of Betelgeuse in February 2020, was accounted starting with the ATel #13341 of 8th December 2019, and a second dust-cloud minimum occurred in August 2020 ATel #13982. After that the luminosity of Betelgeuse underwent small (0.1 mag) oscillations around the visual magnitude 0.65; now the star had a rapid rising particularly evident in the last weeks, reaching Procyon in luminosity near magnitude 0.3. This is the brighter phase after 2017, five years, in fair agreement with the modulating period of Betelgeuse of 5.9 years. The Purkinje effect, which enhances red stars' luminosity to the naked eye, has been avoided in the visual observations with quick-look techniques and with the differential analysis with Aldebaran, of the same color. Airmass corrections have been always included (AAVSO database- https://www.aavso.org/lcg - SGQ, MFB and SRX codes). The V-Band observations showed an overall 0.006 mag/day rising in the last 7 weeks (AAVSO-VOL code). This could be the maximum phase before reaching a new minimum next June 2022, if the pulsations are in phase with the usual period of 1.2 years. The V-band observations in daytime (AAVSO-NOT code) monitored the star in June-August 2021 providing a seamless lightcurve, and this technique can provide data for the forthcoming minimum. Anyway the present rising is not in phase with respect to the 2020's one, accounted in ATel #13601 on March 31, within the usual (until 2020 at least) pulsational regime of 1.2 years. Some evidences of such behavior have been already presented at the XVI Marcel Grossmann Meeting HR1 session, online at https://youtu.be/VmbrE2gYmOM in July 2021, with interesting observational and theoretical discussions. MG XVI session on Betelgeuse Fall and Rise (2021)

B

atel_15300

Title: Fermi-LAT detection of enhanced gamma-ray activity from the FSRQ PMN J0634-2335 Authors: M. Giroletti (INAF/IRA), C. C. Cheung (NRL), on behalf of the Fermi Large Area Telescope Collaboration Date: 28 Mar 2022; 16:23 UT Provenance: Marcello Giroletti ([email protected]) Subjects: Gamma Ray, >GeV, Request for Observations, AGN, Blazar, Quasar Description: The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar PMN J0634-2335, also known as 4FGL J0634.9-2335 (The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. = 98.745837 deg, Decl. = -23.586654 deg (J2000; Petrov et al. 2006, AJ, 131, 1872), and redshift z=1.535 (Ackermann et al. 2011, ApJ, 743, 171). Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on 2022 March 27, with a daily averaged gamma-ray flux (E>100MeV) of (0.70+/-0.15) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of 40 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL). This is the highest daily flux ever observed for this source by the LAT. The measured photon index is 1.96+/-0.14, corresponding to a significantly harder spectrum than the 4FGL value of 2.61+/-0.07. Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. A preliminary light curve can be accessed via the Fermi-LAT Light-Curve Repository at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/lcr/source.html?source_name=4FGL_J0634.9-2335. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Marcello Giroletti ([email protected]). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

B

atel_15390

Title: Optical follow-up of Mrk421 Authors: Roberto Nesci (INAF/IAPS) Date: 21 May 2022; 22:09 UT Provenance: Roberto Nesci ([email protected]) Subjects: Optical, AGN, Blazar Description: After the announcement in ATel #15389 of a flaring activity in Gamma rays of Mrk 421 I observed the source on May 21 2021 with the 30cm telescope of the Foligno Observatory (K56) in the B and V (Johnson) bands. Four nearby comparison stars were taken from the UCAC4 catalog and aperture photometry was made with IRAF/apphot using a 6 arcsec radius. Mrk412 was detected at B=13.54 +-0.03 and V=13.10 +-0.04.

B

atel_15475

Title: Spectroscopic Classification of AT 2022igz as a Type II SN with Keck I/LRIS Authors: S. Tinyanont, K. W. Davis, R. J. Foley (UC Santa Cruz) Date: 27 Jun 2022; 21:26 UT Provenance: Samaporn Tinyanont ([email protected]) Subjects: Optical, Supernovae Description: We report the classification of AT 2022igz from spectroscopic observations with the LRIS spectrograph on the Keck I telescope, made on 2022 June 27 UT. The target was supplied by ZTF. Classifications were performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes ZTF22aahjcmv | 2022igz | 16:08:58.106 | +27:09:59.54 | 0.0314 | II | +1 mo | (1) Notes: The redshift is of the host galaxy KUG 1606+272 obtained from NED. (1) We measure two absorption components from H-alpha at velocities of -7500 and -4000 km/s, respectively.

D

atel_15540

Title: Late epoch near-infrared spectroscopy of V1405 Cas: The emergence of coronal line emission Authors: C. E. Woodward (U. Minnesota, USA), A. Evans (Keele U., UK), D. P.K. Banerjee (Physical Research Laboratory, India) Date: 4 Aug 2022; 13:39 UT Provenance: C.E. Woodward ([email protected]) Subjects: Infra-Red, Nova Description: Referred to by ATel #: 15934, 16089 ATel #15518 reported the resolving of the nova shell of V1405 Cas (= Nova Cas 2021) at GHz frequencies with the VLA on 2022 July 04. As part of an on-going near infrared spectroscopic study of this very slow nova (ATel #14665, #14794), we report late epoch (+514.80 days post-outburst) 0.7 to 4.2 micron spectra obtained on 2021 July 31.54 UT on the 3.2m IRTF telescope using SpeX in cross-dispersed mode with an 0.8 arcsecond slit (R=750) under photometric conditions and moderate seeing (1.1 arcsec at K-band). The NIR spectra at this epoch is dominated by an exceptionally strong He I 1.0830 emission, total integrated observed flux of 1.06E-10 erg/s/cm^2. The emission feature is comprised of three Gaussian components, a strong central core with a Gaussian FWHM of order 862 km/s, and two narrower components with average widths of 422 km/s off set by +/- 850 km/s. Similar structure is evident in the Brackett-alpha, 4.40E-12 ergs/s/cm^2, and Pfund-gamma, 7.27E-13 ergs/s/cm^2, and Paschen-alpha, Paschen-beta, 8.70E-12 ergs/s/cm^2 and the He I 2.058, 9.71e-13 ergs/s/cm^2 lines. The P-Cygni absorptions in the H lines (ATel #14665) and He I lines are no longer detected. The spectral energy distribution shows no evidence for dust formation, and the overall infrared continuum has declined a factor of approximately 10 over the last 363 days. However, now present are broad coronal line emission features from [Ca V] 4.157, [Ca IV] 3.206, [Si VI] 1.966, and [Al IX] 2.040, and [P VII] 1.375 micron. The strength of the emission features over 500 days-post outburst, similar to that seen in other old classical novae such as V1974 Cyg, V382 Vel, V1494 Aql more that 4000 days post eruption (e.g., Helton et al. 2012, ApJ 755, 37), indicate that further synoptic spectroscopic observations of the very late evolutionary stage of V1405 Cas in the infrared is possible which can provide accurate elemental abundance determinations in the ejecta. With future JWST narrow-band imagery and IFU spectroscopy, spatially resolving the shell may also be feasible. These observations were conducted under the NASA IRTF program 2022A004, and we thank the IRTF staff for their assistance.

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atel_15630

Title: Swift/XRT confirms brightening of the X-ray transient 2E 1050.8-6200 Authors: Amar Deo Chandra (IISER Kolkata) Date: 25 Sep 2022; 06:05 UT Provenance: Amar Deo Chandra ([email protected]) Subjects: X-ray, Request for Observations, Transient Description: Referred to by ATel #: 15645, 15646 Following the report of possible serendipitous detection of the X-ray transient 2E 1050.8-6200 using INTEGRAL/JEM-X Galactic Plane observations (ATel# 15624), 1.9 ks Swift/XRT target of opportunity observation was performed in Photon Counting (PC) mode on 2022 September 24 (MJD 59846) beginning at 20:20:34. We detect an X-ray source at the following location: RA/Dec(J2000) = 163.1783, -62.2660 which is equivalent to: RA(J2000) = 10h 52m 42.80s, Dec(J2000) = -62d 15m 57.7s, with an error radius of 3.8 arc-seconds (90% confidence). The location of this source is consistent with the reported location of 2E 1050.8-6200 (ATel# 15624). The estimated averaged count rate during this observation is about 0.2 cts/s. Swift/XRT observations confirm renewed X-ray activity from the transient 2E 1050.8-6200. Follow-up multi-wavelength observations are encouraged. We thank the Swift Team and Observatory Duty Scientists who made these observations possible.

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atel_15725

Title: An exceptionally optical flare of BL Lac on 2022 Oct Authors: J. A. Acosta Pulido, M. Nievas Rosillo, J. Becerra Gonzalez (Instituto de Astrofisica de Canarias, Spain); M. I. Carnerero (Osservatorio Astrofisico di Torino, Italy) Date: 27 Oct 2022; 09:04 UT Provenance: Jose A. Acosta-Pulido ([email protected]) Subjects: Optical, Blazar Description: Referred to by ATel #: 15730 We report on optical observations of BL Lac using the 0.4 m telescope network of Las Cumbres Observatory. A sudden increase of flux was observed on 2022-Oct-20 0:45UT, w.r.t. the previous data taken 4 hours before. Our measurements show an increase in brightness of about 0.45 magnitudes in V and R bands. Afterwards, the source flux increases a bit further in the next 4 hours and then decreases by 0.2 magnitudes after 1 day. Our last observation on 2022-Oct-24 23:46UT shows a similar brightness level as before the flare occurred. Note that the magnitudes reached at the observed maximum (R=11.52 and V=12.08) are above the dramatic outburst in 2020 Aug, as reported by Jorstad et al (2022, Nature, 609, 265). The details of the measurements are as follows: JD=2459870.92 - R=12.14, V=12.64 JD=2459871.53 - R=12.16, V=12.74 JD=2459872.36 - R=11.96, V=12.57 JD=2459872.53 - R=11.55, V=12.14 JD=2459872.70 - R=11.52, V=12.08 JD=2459873.73 - R=11.73, V=12.28 JD=2459876.70 - R=12.07, V=12.58 JD=2459873.73 - R=12.10, V=12.77 Another brightening in the optical range was reported in ATel #15684, happening in the days previous than reported here.

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atel_15840

Title: Spectroscopic confirmation and photometry of the nova candidate PNV J00424067+4115451 Authors: A. Vinokurov, A. Valeev, R. Uklein, O. Maslennikova, A. Sarkisyan (SAO RAS) Date: 2 Jan 2023; 21:39 UT Provenance: Azamat Valeev ([email protected]) Subjects: Optical, Nova, Transient, Variables Description: ATels #15833,#15836 reported the discovery of PNV J00424067+4115451, a new nova candidate in M31. Here, we present the results of our recent optical spectroscopy and photometry of the object. Spectroscopic observations were carried out on 2022 Dec. 30 (MJD=59943.78) with the multi-mode focal reducer SCORPIO-2 mounted at the primary focus of a 6-m SAO RAS telescope. Three subexposures of 300s were obtained with a VPHG1200@540 grism covering the spectral range of about 3650-7300ÅÅ with resolution of 4.5Å. Spectroscopy has revealed a prominent blue continuum with high-order Balmer absorption lines together with deep Fe II, Ca II and relatively weak Na I and Si II absorptions. Emission components in a P-Cyg profile are clearly visible in the Hγ, Hβ, Hα and some Fe II lines, for example Fe II 4924,5018. The FWHMs of the emission components are in range of 1000-1200 km/s, and absorption minimum of the lines is blueshifted by 1050 ± 100 km/s from the emission peak. Direct imaging of the M31 nuclear region in filters B, V and Rc were carried out approximately 1.5 hours before the spectroscopy (MJD=59943.71) using the CCD photometer of the 1-m SAO RAS telescope. The seeing was 1.8-2.3 arcsec during observations. 60 sec exposure per filter were obtained. The measured magnitudes are B = 17.20 ± 0.07, V = 16.81 ± 0.12, Rc = 16.67 ± 0.17. The Rc magnitude indicates an increase in the brightness of the object compared to the values reported by K. Hornoch et al. in ATel #15836. Based on the obtained spectrum and photometry, we classify PNV J00424067+4115451 as Fe II class Nova which has not yet reached its maximum brightness at the time of our observations. The work was performed as part of the government contract of the SAO RAS approved by the Ministry of Science and Higher Education of the Russian Federation. Observations with the SAO RAS telescopes are supported by the Ministry of Science and Higher Education of the Russian Federation. The renovation of telescope equipment is currently provided within the national project "Science and Universities". The spectrum with the line identification

A

atel_15900

Title: Fermi-LAT detection of enhanced gamma-ray activity from the FSRQ GB6 J0342+3858 Authors: Denis Bernard (LLR, Ecole Polytechnique & CNRS / IN2P3), Janeth Valverde (UMBC / NASA GSFC), on behalf of the Fermi Large Area Telescope Collaboration Date: 13 Feb 2023; 13:01 UT Provenance: Denis Bernard ([email protected]) Subjects: >GeV, Request for Observations, AGN, Blazar Description: The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed enhanced gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar GB6 J0342+3858 (also known as 4FGL J0342.2+3858), with coordinates R.A. = 55.567788 deg, Decl. = 38.985075 deg (J2000; Jackson, N., et al. 2007, MNRAS, 376, 371), and redshift z=0.945 (Makarov, V. V., et al. 2019, ApJ, 873, 132). Preliminary analysis indicates that this source was in an elevated gamma-ray emission state on 2023 February 11 from 12:00 - 18:00 UTC, with an averaged gamma-ray flux (E>100MeV) of (0.6+/-0.2) X 10^-6 photons cm^-2 s^-1 (statistical uncertainty only). This corresponds to a flux increase of a factor of 100 relative to the average flux reported in the fourth Fermi-LAT catalog (4FGL-DR3, Abdollahi, S., et al. for the Fermi-LAT collaboration 2022, ApJS, 260, 53). This is the highest LAT daily flux ever observed for this source. The corresponding photon index is 2.01+/-0.19, and is smaller than the 4FGL-DR3 value of 2.26+/-0.11. Because Fermi normally operates in an all-sky scanning mode, regular gamma-ray monitoring of this source will continue. Preliminary Fermi-LAT light curves can be accessed via the Fermi-LAT Light-Curve Repository at https://fermi.gsfc.nasa.gov/ssc/data/access/lat/LightCurveRepository/source.html?source_name=4FGL_J0342.2+3858. We encourage multifrequency observations of this source. For this source, the Fermi-LAT contact person is Denis Bernard ([email protected]). The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.

A

atel_15960

Title: New optical outburst of the blazar S4 0954+65 Authors: Rumen Bachev (IA-NAO, BAS, Bulgaria) Date: 23 Mar 2023; 01:04 UT Provenance: Rumen Bachev ([email protected]) Subjects: Optical, AGN, Blazar Description: Referred to by ATel #: 16030, 16041 The blazar S4 0954+65 has been monitored during the last several nights (2023, March 18th, 19th and 22nd) with the 0.6m telescope of Belogradchik observatory, Bulgaria. The object showed significant brightness increase, reaching an R-band magnitude of about 13.5 during the last night (22-23.03.2023). Significant polarization in the optical was also measured. Our preliminary data are listed below. JD | R-mag (err) | P (err) [%] | EVPA (err) [deg] ---|---|---|--- 2460022.28 | 14.39 (0.03) | 22 (1) | 109 (3) 2460023.28 | 14.79 (0.03) | 19 (1) | 82 (3) 2460026.44 | 13.51 (0.03) | 33 (1) | 104 (3) Further observations are encouraged. This research was partially supported by the Bulgarian National Science Fund of the Ministry of Education and Science under grants KP-06-H28/3 (2018), KP-06-H38/4 (2019), KP-06-KITAJ/2 (2020) and KP-06-PN68/1(2022).

A

atel_16020

Title: A new hard X-ray activity from XTE J1855-026 caught by INTEGRAL Authors: V. Sguera (INAF-OAS Bologna, Italy), L. Sidoli (INAF-IASF Milano, Italy) Date: 28 Apr 2023; 14:38 UT Provenance: Vito Sguera ([email protected]) Subjects: X-ray, Binary Description: XTE J1855-026 is classified as a classical, eclipsing, persistent supergiant high mass X-ray binary, although it is peculiarly characterized by sporadic bright and hard X-ray flares (Atel #2482, Atel #3964). Its enhanced level of hard X-ray activity makes it detectable with IBIS/ISGRI onboard INTEGRAL about 10% of the time (Sidoli & Paizis 2018). The field region of XTE J1855-026 has been recently covered by INTEGRAL observations from 21 April 2023 13:39 UTC to 22 April 2023 16:22 UTC. The source was in the field of view of IBIS/ISGRI with an effective exposure time of about 3 ks. It was detected at about 8 sigma level (25-60 kev) with an average flux of 34.0+/-4.3 mCrab (3.2 x 10-10 erg cm-2 s-1). No significant emission was detected in the band 60-100 keV. The source was again in the IBIS/ISGRI field of view during subsequent observations from 26 April 2023 11:13 UTC to 27 April 2023 13:03 UTC. The effective exposure was about 2 ks. This time the source was not significantly detected and the inferred 2 sigma upper limit is about 10 mCrab (25-60 keV). The reported INTEGRAL observations provide evidence of a recent hard X-ray activity from the source, although it is not possible to constrain its beginning and duration since the source was not in the INTEGRAL field of view during the observations previous to the reported detection.

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atel_16080

Title: JVLA radio detection of SN Ia 2020eyj Authors: Xiaolong Yang (SHAO, China), Zhengwei Liu (YNAO, China), Huanyuan Shan (SHAO, China), Xiangcun Meng (YNAO, China), Bo Zhang (SHAO, China), Jun Yang (OSO/Chalmers University of Technology, Sweden) Date: 11 Jun 2023; 14:13 UT Provenance: Xiaolong Yang ([email protected]) Subjects: Radio, Supernovae Description: Following the identification of the first radio-detected SN Ia 2020eyj (Kool et al. 2023), we report individual and further radio observational results with Karl G. Jansky Very Large Array (JVLA). We obtained two datasets from the NRAO archive, which were observed on 2022 April 14 (Project Code: 22A-472; PI: Javier Moldon) and June 26 (Project Code: 22A-497; PI: Javier Moldon), i.e. 767 and 840 days since discovery, respectively. Both observations were conducted at C-band (the central frequency is 6 GHz) with a bandwidth of 2 GHz. These observations yield clear detection of a radio source at the position of SN 2020eyj with peak flux densities 62.9 +- 8.2 and 63.0 +- 10.1 microJy, respectively. We transfer the 6 GHz peak flux density to 5.1 GHz via the measured in-band spectral indexes and find no evidence for statistically significant radio luminosity decline by comparing JVLA with e-MERLIN observations (see the attached Figure, https://drive.google.com/file/d/1gWQ1_--4EmIIAF9P00tp6RKS9y7QN4vS/view?usp=sharing). Further observations are proposed to unveil the radio evolution.

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atel_16140

Title: ASAS-SN Discovery of Long-term fading in Mrk 926 and SCAT Classification as an Optical Changing-Look AGN Authors: J. T. Hinkle, M. E. Huber, A. V. Payne, B. J. Shappee (IfA, Hawai'i), M. A. Tucker (Ohio State), K. Auchettl (University of Melbourne), A. Do, W. B. Hoogendam (IfA, Hawai'i), K. Z. Stanek, C. S. Kochanek, T. A. Thompson, J. M. M. Neustadt (Ohio State), T. W.-S. Holoien (Carnegie Observatories), J. L. Prieto (Diego Portales; MAS), S. Dong (KIAA-PKU) Date: 18 Jul 2023; 23:34 UT Provenance: Jason Hinkle ([email protected]) Subjects: Optical, AGN, Black Hole Description: During normal operations of the All-Sky Automated Survey for Supernovae (ASAS-SN; Shappee et al. 2014, Kochanek et al. 2017) a large (~0.5 mag) decrease in brightness was observed for the AGN Mrk 926. The long-term ASAS-SN and Asteroid Terrestrial-impact Last Alert System (ATLAS; Tonry et al. 2018) light curves show that Mrk 926 has been steadily fading in brightness for ~5.5 years. This flux decrease is accompanied by a decrease in the optical variability amplitude. Mrk 926 was first identified as a Seyfert galaxy by Ward et al. (1978), with subsequent spectroscopic follow-up suggesting a Seyfert 1/1.5 classification (Durret & Bergeron 1988, Véron-Cetty & Véron 2006, Kollatschny & Zetzl 2010). Because of the large flux decrease, we obtained a spectrum with the Supernova Integral Field Spectrograph (SNIFS; Lantz et al. 2004) on the University of Hawaii 88-inch telescope on 2023-07-16 as part of the Spectroscopic Classification of Astronomical Transients (SCAT) program (ATel #11444, Tucker et al. 2022). Compared to an archival SDSS spectrum taken in December 2001, the spectrum is redder and shows significantly weaker broad H-beta and other higher order Balmer lines. The broad H-alpha line flux has also decreased and it appears that Mrk 926 has changed type and is now a Type 1.8/1.9 Seyfert. A comparison of the two spectra can be found below. We have requested Swift ToO observations and are obtaining follow-up spectra. We encourage further follow-up of this source, particularly with high S/N spectroscopy. Comparison of SNIFS and SDSS Spectra

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atel_16200

Title: Fading of the black hole transient MAXI J1820+070 in X-rays and UV Authors: Jeroen Homan (Eureka Scientific), M. Cristina Baglio, Payaswini Saikia, Kevin Alabarta, David M. Russell, D. M. Bramich (NYU Abu Dhabi), Fraser Lewis (Faulkes Telescope Project & Astrophysics Research Institute, LJMU), Maureen van den Berg (Center for Astrophysics | Harvard & Smithsonian), Richard M. Plotkin (University of Nevada, Reno), and Jeremy Hare (NASA GSFC/CUA/CRESST II) Date: 23 Aug 2023; 09:58 UT Provenance: Jeroen Homan ([email protected]) Subjects: Ultra-Violet, X-ray, Black Hole, Transient Description: Following the observed fading of the black hole transient MAXI J1820+070 into a deeper optical quiescent state (ATel #16192) we observed the source with the X-ray Telescope onboard the Neil Gehrels Swift Observatory. Observations were performed in Photon Counting mode between August 20 07:02 UTC and August 21 21:37 UTC for a total exposure of 2.66 ks. In the 0.5-10 keV image we detect 5 photons within a 20 arcsec extraction radius centered on the source; only 0.9+/-0.1 photons would have been expected based on the background in the vicinity of the source (annulus with ~19 arcmin^2 area). There is only a 0.2% probability of detecting 5 photons for the measured background level. The resulting background-subtracted count rate is (1.5+/-0.7)e-3 cts/s. This is a factor of ~10 lower than the average count rate observed in Swift/XRT observations made during the second half of 2022. We used PIMMS to convert the above count rate into an unabsorbed 0.5-10 keV flux, assuming a power-law spectrum with an index of 2.1 and an nH of 1.1e21 cm^-2 (Shaw et al. 2021, ApJ, 907, 34). This yields a flux of (6+/-3)e-14 erg/s/cm^2. For a distance of 3 kpc (Atri et al. 2020, MNRAS, 493, L81) this corresponds to a luminosity of (6+/-3)e31 erg/s. Given the orbital period of MAXI J1820+070 (16.5 hr; Torres et al. 2019, ApJ, 882, L21), this value is consistent (within scatter) with the empirical relation between the quiescent X-ray luminosity and orbital period for black hole X-ray binaries (Armas Padilla et al. 2014, MNRAS, 444, 902). Observations with Chandra or XMM-Newton are required to better characterize the quiescent properties of MAXI J1820+070. Swift/UVOT observed the source in the U and UVW2 filters, resulting in 520 s and 1.5 ks exposures in the two filters, respectively. The source is detected in both images. We analyzed the images with the HEASOFT tool uvotsource using a 5 arcsec aperture, getting the following Vega magnitudes: U=18.98+/-0.13, UVW2=20.69+/-0.28, showing that the source is getting fainter also at UV frequencies. For comparison, a U magnitude of 18.02 +/- 0.05 was measured on 1 November 2022 and UVW2 magnitude of 18.76+/-0.09 on 1 October 2022. We thank the Swift team for approving and executing our DDT observations of MAXI J1820+070.

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atel_16260

Title: New outburst of the black-hole low-mass X-ray binary GX 339-4 detected with XB-NEWS and Swift/XRT Authors: Kevin Alabarta (NYU Abu Dhabi), Jeroen Homan (Eureka Scientific), David M. Russell (NYU Abu Dhabi), Sara Motta and M. Cristina Baglio (INAF-OAB), Payaswini Saikia, D. M. Bramich and Sandeep Rout (NYU Abu Dhabi), and Fraser Lewis (Faulkes Telescope Project & Astrophysics Research Institute, LJMU) Date: 28 Sep 2023; 06:37 UT Provenance: Kevin Alabarta ([email protected]) Subjects: Optical, X-ray, Binary, Black Hole, Transient Description: Referred to by ATel #: 16302, 16424, 16425 GX 339-4 is a black-hole low-mass X-ray binary undergoing outbursts with recurrence times of approximately 1-2 years. During the last few months, GX 339-4 has shown low-level X-ray and optical activity, with fluxes slightly higher than those normally observed in quiescence (ATel #16096). Here we report on recent optical and X-ray observations that indicate that GX 339-4 has started to deviate significantly from the previously reported low-level activity and has entered an outburst phase. The optical observations were performed with the 1m and 2m optical telescopes of the Las Cumbres Observatory (LCO) network and light curves can be seen in the figure linked below. Since August 15 (MJD 60171.58), the optical flux (with magnitudes V ~ 19.1, R ~ 18.3 and i' ~ 18.2) has been brightening at a rate of ~0.03 mag/day (i' and R bands) and 0.04 mag/day (V band). On September 16 (MJD 60203.43), XB-NEWS measured optical magnitudes of GX 339-4 in the V, R and i' bands of 18.59 +/- 0.01, 17.98 +/- 0.01 and 17.66 +/- 0.01, respectively. These magnitudes are significantly brighter than those observed in the last months. Since then, GX 339-4 has brightened further to V = 17.64 +/- 0.01, R = 17.23 +/- 0.01 and i' = 17.12 +/- 0.01 on September 24, 2023 (MJD 60211.49). The increase in flux since September 16 is higher at shorter wavelengths, ΔV = 0.95 +/- 0.01, ΔR = 0.75 +/- 0.01 and Δi' = 0.54 +/- 0.01, suggesting an important contribution of the accretion disc to the brightening of the source and the beginning of a new outburst. GX 339-4 has also been monitored with the Swift/XRT on a regular basis. The observed X-ray count rate evolution is similar to that in the optical (see the light curve figure). After reaching a local minimum around August 10 (MJD 60166) the X-ray count rates have increased by a factor of 15, reaching 0.24 counts/s on September 23 (MJD 60210). Multi-wavelength observations are encouraged to study the rise of the outburst. The LCO observations of GX 339-4 were performed as part of an ongoing monitoring program of ~50 low-mass X-ray binaries (Lewis et al. 2008). LCO images are processed and reduced, and magnitudes are extracted and calibrated using a real-time data analysis pipeline, the "X-ray Binary New Early Warning System" (XB-NEWS; see Russell et al. 2019, Goodwin et al. 2020 and ATel #13451 for details). This material is based upon work supported by Tamkeen under the NYU Abu Dhabi Research Institute grant CASS (Center for Astrophysics and Space Science). A link to the light curve is below. X-ray (top) and optical (bottom) light curves of GX 339-4

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atel_16350

Title: A follw up for ATel number 16349 A Possible Optical Counterpart Discovery of NuStar J 053449+2126.0 with RTT150 Authors: E. N.Ercan (Bogazici University), E. Aktekin Caliskan ( Suleyman Demirel University), M. H.Erkut (Bogazici University), A. Farhan (self employed), E. P.J. van den Heuvel (Amsterdam University) Date: 27 Nov 2023; 16:36 UT Provenance: E.Nihal Ercan ([email protected]) Subjects: Optical, Quasar Description: A Followup for ATel 16349 The log of our photometric observations, characteristics of the filters used, and magnitude values are as follows: 2022/03/25: with Filter Bessel B, Magnitude 21.32+/-0.91, Wavelengt 433nm, FWHM 114 nm. 2022/12/20: with Filter Bessel B, Magnitude 19.84 +/-0.27, Wavelength 433 nm, FWHM 114 nm. 2022/12/20: with Filter V, Magnitude 18.90+/-0.22, Wavelength 519 nm, FWHM 100 nm. 2022/12/20: with Filter R, Magnitude 18.37+/-0.21, Wavelength 600 nm, FWHM 128 nm. 2022/12/20: with Filter I, Magnitude 18.02+/-0.18, Wavelength 782 nm, FWHM 347nm . The exposure time for each was 900 sec. On the other hand, The log of our spectroscopic observations is as follows: Observation No; Slit centre (alpha: hr, min, sec; delta: ( 0 ‘,’’), Exposure time (sec) 1) 2022/12/20 ; 05 34 49.60; +21 26 01.64 3600 sec 2) 2022/12/23: 05 34 49.60; +21 26 01.64 3600 sec 3) 2022/12/23 : 05 34 49.60; +21 26 01.64 3600 sec 4) 2022/12/23: 05 34 49.60; +21 26 01.64 3600 sec 5) 2022/12/23 : 05 34 49.60; +21 26 01.64 3600 sec Among the possible redshift values, we obtained z=2.2144+/-0.0066 for the Lyman-alpha line that we fitted at its observed wavelength of 3904+/-8 Angstrom. Throughout the observations, the emission lines we identified for z =2.2 (approx.) were Lyman-alpha, Si IV+O IV), N IV), C IV, N III), and absorption line Fe II.

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atel_16410

Title: Discovery of a Probable Nova in M83 Authors: K. Hornoch (Astronomical Institute, Ondrejov, Czech Republic), H. Kucakova (Charles University, Prague, Czech Republic), A. W. Shafter (SDSU) Date: 17 Jan 2024; 20:06 UT Provenance: Allen W. Shafter ([email protected]) Subjects: Optical, Nova, Transient Description: Referred to by ATel #: 16411 We report the discovery of a probable nova in M83 on a co-added 540-s R-band CCD frame taken on 2024 Jan. 13.374 UT with the Danish 1.54-m telescope at La Silla. The new object designated PNV J13370709-2957165 is located at R.A. = 13h37m07s.09, Decl. = -29o57'16".5 (equinox 2000.0), which is 80.2" east and 319.8" south of the center of M83 (see link to finding chart below; crop of a confirmation image taken on Jan. 16.374 UT with the same instrumentation is shown in the upper-right corner). The following R-band magnitudes were obtained using the Danish 1.54-m telescope at La Silla: 2018 Mar. 26.207 UT, [24.0; 2024 Jan. 13.374, 21.4 ± 0.25; 16.374, 21.4 ± 0.2; 17.375, 21.4 ± 0.2. This work is based on data collected with the Danish 1.54-m telescope at the ESO La Silla Observatory. Finding chart

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