//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28155 SUBJECT: GRB 200723A: Fermi GBM Final Real-time Localization DATE: 20/07/23 16:45:46 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 16:35:24 UT on 23 Jul 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 200723A (trigger 617214929.786984 / 200723691). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 249.5, Dec = 58.1 (J2000 degrees, equivalent to J2000 16h 37m, 58d 06'), with a statistical uncertainty of 4.0 degrees. The angle from the Fermi LAT boresight is 42.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200723691/quicklook/glg_skymap_all_bn200723691.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200723691/quicklook/glg_healpix_all_bn200723691.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn200723691/quicklook/glg_lc_medres34_bn200723691.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28156 SUBJECT: GRB 200723A: BALROG localization (Fermi Trigger 617214929 / GRB 200723691) DATE: 20/07/23 17:05:27 GMT FROM: Jochen Greiner at MPE,Garching F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report: The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 617214929 at 16:35:24 on 23 July 2020 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60). The best-fit position (1 sigma statistical errors) is: RA(2000.0) = 233.5+/-8.3 deg Decl.(2000.0) = 61.0+/-2.7 deg We estimate an additional systematic error of 2 deg. Further details are available at: https://grb.mpe.mpg.de/grb/GRB200723691/ The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB200723691/healpix The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB200723691/json //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28157 SUBJECT: Fermi GRB 200723A: Global MASTER-Net observations report DATE: 20/07/23 17:30:26 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), H.Levato (Instituto de Ciencias Astronomicas, de la Tierra y del Espacio ICATE), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-Tunka robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Applied Physics Institute, Irkutsk State University) started inspect of the Fermi GRB 200723A ( Fermi GBM team, GCN 28155) errorbox 61 sec after notice time and 87 sec after trigger time at 2020-07-23 16:36:52 UT, with upper limit up to 19.3 mag. The observations began at zenith distance = 12 deg. The sun altitude is -18.6 deg. The galactic latitude b = 33 deg., longitude l = 90 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1406982 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 98 | 2020-07-23 16:36:52 | MASTER-Tunka | (18h 25m 28.78s , +57d 41m 39.0s) | P| | 20 | 16.9 | 138 | 2020-07-23 16:37:33 | MASTER-Tunka | (17h 10m 07.98s , +60d 43m 48.8s) | P| | 20 | 17.3 | 182 | 2020-07-23 16:38:12 | MASTER-Tunka | (17h 10m 03.28s , +60d 42m 46.7s) | P| | 30 | 17.7 | 237 | 2020-07-23 16:39:01 | MASTER-Tunka | (17h 10m 09.23s , +60d 42m 45.4s) | P| | 40 | 17.8 | 301 | 2020-07-23 16:40:00 | MASTER-Tunka | (17h 10m 05.43s , +60d 44m 21.0s) | P| | 50 | 18.1 | 381 | 2020-07-23 16:41:10 | MASTER-Tunka | (17h 10m 05.24s , +60d 42m 58.8s) | P| | 70 | 18.4 | 465 | 2020-07-23 16:42:39 | MASTER-Tunka | (16h 54m 47.92s , +59d 52m 11.4s) | C | 60 | 19.3 | 581 | 2020-07-23 16:44:35 | MASTER-Tunka | (16h 52m 45.47s , +61d 52m 08.0s) | C | 60 | 18.9 | 690 | 2020-07-23 16:45:54 | MASTER-Tunka | (16h 36m 47.21s , +57d 55m 40.5s) | P| | 120 | 18.9 | 845 | 2020-07-23 16:48:14 | MASTER-Tunka | (16h 36m 53.38s , +57d 55m 51.2s) | P| | 150 | 19.0 | 1029 | 2020-07-23 16:51:03 | MASTER-Tunka | (16h 36m 49.68s , +57d 57m 08.3s) | P| | 180 | 19.0 | 1228 | 2020-07-23 16:54:22 | MASTER-Tunka | (16h 36m 49.18s , +57d 55m 45.7s) | P| | 180 | 19.0 | 1538 | 2020-07-23 17:00:33 | MASTER-Tunka | (16h 54m 46.63s , +59d 52m 54.7s) | C | 60 | 19.0 | 1619 | 2020-07-23 17:01:53 | MASTER-Tunka | (17h 10m 54.87s , +59d 51m 40.0s) | C | 60 | 19.0 | 1698 | 2020-07-23 17:03:13 | MASTER-Tunka | (16h 52m 36.95s , +61d 50m 49.9s) | C | 60 | 19.0 | 1778 | 2020-07-23 17:04:32 | MASTER-Tunka | (17h 09m 48.78s , +61d 50m 45.5s) | C | 60 | 19.1 | 2691 | 2020-07-23 17:19:45 | MASTER-Tunka | (17h 10m 50.96s , +59d 50m 26.8s) | C | 60 | 18.5 | 2771 | 2020-07-23 17:21:05 | MASTER-Tunka | (17h 09m 50.15s , +61d 50m 39.3s) | C | 60 | 19.1 | 2867 | 2020-07-23 17:22:42 | MASTER-Tunka | (17h 00m 03.82s , +58d 20m 47.8s) | C | 60 | 19.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28159 SUBJECT: GRB 200723A: GOTO candidate afterglow and host galaxy DATE: 20/07/24 10:33:09 GMT FROM: Ben Gompertz at U of Warwick B. Gompertz (1); K. Wiersema (1); D. K. Galloway (2); R. Starling (3); J. Lyman (1); K. Ackley (2); Y.-L. Mong (2); D. Steeghs (1); V.Dhillon (4); P. O'Brien (3); G. Ramsay (5); D. Pollacco (1); E. Thrane (2); S. Poshyachinda (6); R. Kotak (7); L. Nuttall (8); E. Pall\'e (9); K. Ulaczyk (1); R. Cutter (1); A. Levan (1); T. Marsh (1); R. West (1); E. Stanway (1); T. Killestein (1); A. Casey (2); M. Brown (2); B. Muller (2); M. Dyer (4); J. Mullaney (4); E. Daw (4); S. Littlefair (4); J. Maund (4); L. Makrygianni (4); U. Burhanudin (4); R. Eyles (3); S. Tooke (3); S. Aukkaravittayapun (6); U. Sawangwit (6); S. Awiphan (6); D. Mkrtichian (6); P. Irawati (6); S. Mattila (7); T. Heikkil\"a (7); E. Rol (1) ((1) Warwick University, (2) Monash University, (3) University of Leicester, (4) University of Sheffield, (5) Armagh Observatory & Planetarium, (6) National Astronomical Research Institute of Thailand, (7) University of Turku, (8) University of Portsmouth, (9) Instituto de Astrofisica de Canarias) report on behalf of the GOTO collaboration: We carried out observations with the Gravitational-wave Optical Transient Observer (GOTO) in response to GRB 200723A (Fermi GBM; GCN 28155). We made a series of 4x90 s exposures using our wide L-band filter (400-700 nm) covering the Fermi GBM error box (GCN 28155), with midtime 22:42:55 UT on 23 July 2020. Using a difference imaging analysis with recent survey observations of the same pointings as reference, we detect an uncatalogued source in a tiled observation taken at 21:25 UT (4.8 hours after trigger) with a magnitude of L = 18.5 ± 0.05 mag based on PS1 catalogue calibrators located at (J2000): RA 16:18:34.973 Dec +60:19:16.21 This source is coincident with a galaxy in the 2MASS redshift survey (Huchra et al, 2012) at a redshift of z = 0.0557. Given the large Fermi GBM uncertainty region, the probability that this source is an unrelated transient is large. We have registered it with the TNS with the ID AT2020qer. A previous GOTO observation taken on July 17 23:28:49 UT places a limiting magnitude of L > 19.2 (5 sigma) on this source 6 days prior to the Fermi GBM trigger. GOTO is operated at the La Palma observing facilities of the University of Warwick on behalf of a consortium including the University of Warwick, Monash University, Armagh Observatory, the University of Leicester, the University of Sheffield, the National Astronomical Research Institute of Thailand (NARIT) and the Instituto de Astrofisica de Canarias (IAC) (https://goto-observatory.org ) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28160 SUBJECT: GRB 200723A: Swift ToO observations DATE: 20/07/24 13:47:15 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/GBM GRB 200723A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021019 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/GBM event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 28161 SUBJECT: GRB 200723A: ATLAS observations of GOTO candidate AT2020qer DATE: 20/07/24 18:21:59 GMT FROM: Ken Smith at Queen's University Belfast K. W. Smith, S. Srivastav, O. McBrien, S. J. Smartt, J. Gillanders, P. Clark, M. Fulton, D. O'Neill, D. R. Young, M. McCollum (QUB), A. Townsend (University of Manchester, QUB), T.-W. Chen (Stockholm), J. Anderson (ESO), L. Denneau, A. Heinze, J. Tonry, H. Weiland (IfA, University of Hawaii), B. Stalder (LSST), A. Rest (STScI), D. E. Wright (University of Minnesota) The transient AT2020qer reported by Gompertz et al (GCN 28159) as a possible counterpart to GRB 200723A (Fermi GBM; GCN 28155), was detected independently by ATLAS, the twin telescope system on Haleakala and Mauna Loa as part of normal sky operations (Tonry et al. 2018, PASP, 130f4505, Smith et al. 2020, PASP, 132f1014) on 2020-07-24.32 (MJD 59054.32). Forced photometry at that position shows clear, rising activity before the GRB event. ATLAS forced photometry: MJD dt m dm filter 59048.36523 -5.33 19.50 0.15 c 59048.36843 -5.32 20.13 0.24 c 59048.37442 -5.32 19.36 0.14 c 59048.40300 -5.29 19.47 0.15 c 59050.33364 -3.36 18.89 0.09 o 59050.33733 -3.35 19.10 0.11 o 59050.34287 -3.35 18.95 0.10 o 59050.35486 -3.34 19.01 0.10 o 59054.31747 0.63 18.18 0.06 o 59054.32069 0.63 18.20 0.05 o 59054.32670 0.64 18.34 0.06 o 59054.33871 0.65 18.27 0.06 o where dt is the time difference between ATLAS MJD and the GRB trigger. We therefore conclude that AT2020qer is unrelated to GRB 200723A and is probably a young supernova candidate.