The Astronomer's Telegram: Top ATels
https://www.astronomerstelegram.org
For reporting and commenting upon new observations of astronomical transients by the professional astrophysics community. en-us ATel 16538: An HI spectroscopic distance constraint on Swift J151857.0-572147
https://www.astronomerstelegram.org/?read=16538
B. J. Burridge, J. C.A. Miller-Jones, A. Bahramian, S. Prabu, F. Carotenuto, T. D. Russell, F. Cowie, R. P. Fender, on behalf of the X-KAT collaboration B. J. Burridge, J. C.A. Miller-Jones, A. Bahramian, S. Prabu, F. Carotenuto, T. D. Russell, F. Cowie, R. P. Fender, on behalf of the X-KAT collaboration benjamin.burridge@postgrad.curtin.edu.au Credentialed by: James Miller-Jones (james.miller-jones@curtin.edu.au) The Astronomer's Telegram ATel16538 The recently discovered X-ray transient Swift J151857.0-572147 (GCN #35849, #35835, ATel #16500, #16506, #16516) is speculated to be a black hole X-ray binary candidate (ATel #16519). ... 2024-03-18T14:25:33-00:00 ATel 16537: Detection of Very high energy gamma-ray flare from the blazar Mrk 421 with MACE
https://www.astronomerstelegram.org/?read=16537
K K Yadav on behalf of MACE team K K Yadav on behalf of MACE team kkyadav@barc.gov.in Credentialed by: Kuldeep Yadav (kkyadav@barc.gov.in) The Astronomer's Telegram ATel16537 MACE (Major Atmospheric Cherenkov Experiment) has detected a giant gamma-ray flaring activity from a nearby blazar Mrk 421 (z=0.031, RA: 11h 05m 37.12s, Dec: 38o 04'3.5'') at very high energies on the night of March 16, 2024. ... 2024-03-18T13:51:00-00:00 ATel 16536: Fermi-LAT detection of renewed gamma-ray activity from the FSRQ blazar PKS 0308-611
https://www.astronomerstelegram.org/?read=16536
Denis Bernard, on behalf of the Fermi Large Area Telescope Collaboration Denis Bernard, on behalf of the Fermi Large Area Telescope Collaboration denis.bernard@in2p3.fr Credentialed by: Denis Bernard (Denis.bernard@in2p3.fr) The Astronomer's Telegram ATel16536 The Large Area Telescope (LAT), one of the two instruments on the Fermi Gamma-ray Space Telescope, has observed renewed gamma-ray activity from a source positionally consistent with the flat-spectrum radio quasar PKS 0308-611, also known as 4FGL J0309.9-6058 (The Fermi-LAT collaboration 2020, ApJS, 247, 33), with coordinates R.A. ... 2024-03-17T07:49:57-00:00 ATel 16535: VERITAS Detection of Elevated VHE Emission from IC 310
https://www.astronomerstelegram.org/?read=16535
Amy Furniss for the VERITAS Collaboration Amy Furniss for the VERITAS Collaboration afurniss@ucsc.edu Credentialed by: Amy Furniss (afurniss@ucsc.edu) The Astronomer's Telegram ATel16535 We report the VERITAS detection of very-high-energy (VHE; > 100 GeV) emission from the active galactic nucleus IC 310 (z=0.0189, RA: 03 16 43.0 Dec: +41 19 29, J2000). ... 2024-03-16T00:12:07-00:00 ATel 16534: Optical spectrum and photometry of PKS 0446+11 located inside the IceCube-240105A error region with GRANDMA
https://www.astronomerstelegram.org/?read=16534
A. Coleiro, T. Pradier, M. Masek, S. Karpov, M. Prouza, C. Adami, J. Schmitt,, S. Antier, I. Tosta e Melo, P. Hello, D. Turpin, M. Coughlin, C. Andrade, P-A Duverne, N. Guessoum, D. Dornic, M. Lamoureux A. Coleiro, T. Pradier, M. Masek, S. Karpov, M. Prouza, C. Adami, J. Schmitt,, S. Antier, I. Tosta e Melo, P. Hello, D. Turpin, M. Coughlin, C. Andrade, P-A Duverne, N. Guessoum, D. Dornic, M. Lamoureux alexis.coleiro@u-paris.fr Credentialed by: Alexis Coleiro (alexis.coleiro@u-paris.fr) The Astronomer's Telegram ATel16534 We report optical observations of the flat-spectrum radio quasar PKS 0446+11 located within the 90% error region of the neutrino event IceCube-240105A (GCN #35485 and #35498). ... 2024-03-15T17:30:31-00:00 ATel 16533: Detection of enhanced very-high-energy gamma-ray emission from Markarian 421
https://www.astronomerstelegram.org/?read=16533
Thomas Tavernier, in the behalf of SST-1M Consortium Thomas Tavernier, in the behalf of SST-1M Consortium tavernier@fzu.cz Credentialed by: Thomas Tavernier (tavernier@fzu.cz) The Astronomer's Telegram ATel16533 We report a significant increase in gamma-ray flux from Markarian 421 above 2 TeV. This observation was conducted through stereo observations using the 2 SST-1M IACTs currently in commissioning at the Ondrejov Observatory. ... 2024-03-15T16:55:47-00:00 ATel 16532: XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a plausible optical counterpart LP 593-21
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M. Yoshimoto, K. Hayashi, Y. Kanemaru, S. Ogawa, T. Yoshida, K. Akasu, M. Audard, E. Behar, S. Inoue, T. Kohmura, Y. Maeda, M. Mizumoto, N. Nemoto, M. Nobukawa, K. Pottschmidt, M. Shidatsu, Y. Terada, Y. Terashima, Y. Tsuboi, H. Uchida, T. Yoneyama M. Yoshimoto, K. Hayashi, Y. Kanemaru, S. Ogawa, T. Yoshida, K. Akasu, M. Audard, E. Behar, S. Inoue, T. Kohmura, Y. Maeda, M. Mizumoto, N. Nemoto, M. Nobukawa, K. Pottschmidt, M. Shidatsu, Y. Terada, Y. Terashima, Y. Tsuboi, H. Uchida, T. Yoneyama tsuboi@phys.chuo-u.ac.jp Credentialed by: Yohko Tsuboi (tsuboi@phys.chuo-u.ac.jp) The Astronomer's Telegram ATel16532 XRISM/Xtend Transient Search (XTS) detected an X-ray flare from a new X-ray source candidate XRISM J0335+0025 at 2024-03-09 TT. The source position is determined to be (R.A., Dec.) = (53.897 deg, 0.422 deg) with a systematic uncertainty of ~ 40 arcsec. ... 2024-03-15T13:38:28-00:00 ATel 16531: GRANDMA follow-up observations of the EP X-ray transient (EP240305a)
https://www.astronomerstelegram.org/?read=16531
S. Antier, X. Wang, W.-M. Yuan, H-B Eggenstein, M. Freeberg, F. Navarete, L. Fraga, Y. Jongen, M. Masek, S. Karpov, B. Gendre, J. Hambsch, J-P Vignes, S. Vanaverke, J-L Virlichie, J. Cazard, P. Traverse, H. Roy, A. Taylor, I. Tosta e Melo, P. Hello, D. Turpin, T. Pradier, M. Coughlin, C. Andrade, P-A Duverne, T. Eposito, A. Perrocheau S. Antier, X. Wang, W.-M. Yuan, H-B Eggenstein, M. Freeberg, F. Navarete, L. Fraga, Y. Jongen, M. Masek, S. Karpov, B. Gendre, J. Hambsch, J-P Vignes, S. Vanaverke, J-L Virlichie, J. Cazard, P. Traverse, H. Roy, A. Taylor, I. Tosta e Melo, P. Hello, D. Turpin, T. Pradier, M. Coughlin, C. Andrade, P-A Duverne, T. Eposito, A. Perrocheau sarah.antier@oca.eu Credentialed by: Antier Sarah (sarah.antier@oca.eu) The Astronomer's Telegram ATel16531 We performed a target of opportunity observations with GRANDMA and its science Kilonova-catcher (KNC) on the X-ray flare EP240305a detected by Einstein Probe (EP) WXT on March 5 2024 (ATel #16509) and followed by Swift XRT (Atel #16514). ... 2024-03-15T09:15:33-00:00 ATel 16530: Discovery of a Probable Nova in M31
https://www.astronomerstelegram.org/?read=16530
K. Hornoch, A. W. Shafter K. Hornoch, A. W. Shafter k.hornoch@centrum.cz Credentialed by: Allen W. Shafter (ashafter@sdsu.edu) The Astronomer's Telegram ATel16530 We report the discovery of a probable nova found during our survey of the central region of M31. The object was discovered on a co-added 900-s R-band CCD frame taken on 2024 Mar. ... 2024-03-14T19:45:34-00:00 ATel 16529: Optical spectroscopic follow up of the EP X-ray transient, EP240305a (EPW20240305aa), with the Southern African Large Telescope (SALT)
https://www.astronomerstelegram.org/?read=16529
I. M. Monageng, P. A. Charles, D. A.H. Buckley, W. Yuan, D. Y. Li and H. Y. Liu I. M. Monageng, P. A. Charles, D. A.H. Buckley, W. Yuan, D. Y. Li and H. Y. Liu itu@saao.ac.za Credentialed by: Itumeleng Monageng (itu@saao.ac.za) The Astronomer's Telegram ATel16529 On 09 March 2024 at 21:58:30 UTC we performed follow-up observations of the possible optical counterpart of the new X-ray flare source, EP240305a (ATel #16509 and ATel #16514), with the Southern African Large Telescope (SALT) under the SALT transient follow-up programme (2021-2-LSP-001). ... 2024-03-14T14:58:45-00:00