//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32455 SUBJECT: GRB 220810A: Fermi GBM Final Real-time Localization DATE: 22/08/10 23:26:25 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 23:15:42 UT on 10 Aug 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220810A (trigger 681866147.080906 / 220810969). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 309.4, Dec = 2.7 (J2000 degrees, equivalent to J2000 20h 37m, 2d 42'), with a statistical uncertainty of 1.6 degrees. The angle from the Fermi LAT boresight is 69.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220810969/quicklook/glg_skymap_all_bn220810969.png The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220810969/quicklook/glg_healpix_all_bn220810969.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220810969/quicklook/glg_lc_medres34_bn220810969.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32456 SUBJECT: Fermi GRB 220810A: Global MASTER-Net observations report DATE: 22/08/11 00:15:15 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (Lomonosov Moscow State University, SAI, Physics Department), R. Podesta, C.Lopez, F. Podesta, C.Francile (Observatorio Astronomico Felix Aguilar OAFA), R. Rebolo, M. Serra (The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), O.A. Gres, N.M. Budnev (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 220810A ( Fermi GBM team, GCN 32455) errorbox 445 sec after notice time and 476 sec after trigger time at 2022-08-10 23:23:38 UT, with upper limit up to 18.3 mag. The observations began at zenith distance = 39 deg. The sun altitude is -71.2 deg. The galactic latitude b = -22 deg., longitude l = 49 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2053838 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 521 | 2022-08-10 23:23:38 | MASTER-SAAO | (20h 45m 02.76s , +02d 31m 33.6s) | C | 90 | 17.6 | 656 | 2022-08-10 23:25:37 | MASTER-SAAO | (20h 36m 27.23s , +02d 32m 24.0s) | C | 120 | 17.8 | 821 | 2022-08-10 23:25:37 | MASTER-SAAO | (20h 36m 27.24s , +02d 32m 24.0s) | C | 450 | 18.3 | Coadd 821 | 2022-08-10 23:28:08 | MASTER-SAAO | (20h 36m 30.98s , +02d 34m 05.9s) | C | 150 | 17.9 | 1018 | 2022-08-10 23:31:09 | MASTER-SAAO | (20h 36m 24.61s , +02d 33m 36.9s) | C | 180 | 17.4 | 1228 | 2022-08-10 23:34:40 | MASTER-SAAO | (20h 36m 24.10s , +02d 34m 44.8s) | C | 180 | 17.9 | 1438 | 2022-08-10 23:38:10 | MASTER-SAAO | (20h 36m 29.40s , +02d 33m 51.2s) | C | 180 | 17.8 | 1649 | 2022-08-10 23:41:41 | MASTER-SAAO | (20h 36m 23.40s , +02d 32m 58.0s) | C | 180 | 17.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32460 SUBJECT: GRB 220810A: MeerLICHT detection of two afterglow candidates DATE: 22/08/12 15:23:28 GMT FROM: Simon de Wet at UCT S. de Wet (UCT), P.J. Groot (Radboud/UCT/SAAO), D. Pieterse (Radboud), P.M. Vreeswijk (Radboud), A.J. Levan (Radboud) and D.B. Malesani (Radboud and DAWN/NBI) report on behalf of the MeerLICHT consortium: Following the detection of GRB 220810A by Fermi/GBM (Fermi GBM team, GCN 32455), the 0.6 m wide-field MeerLICHT optical telescope began a series of automatically-triggered 60 s q-band exposures of a number of fields encompassing the GBM error box. Observations began approximately 14 minutes post-trigger at 23:30:01 UT on 2022 August 10, and continued for an hour. A total of 20 fields encompassing a cumulative probability of 58% were observed once each. Within our difference-imaging products for this dataset we identify two new transient candidates with the following coordinates, brightness, and observing times: +---------------------------+-------------------------+----------------+------------------+----------+ | RA (J2000) | Dec (J2000) | Mag (AB) | 5-sigma limiting | UT time | | | | | mag (AB) | | +---------------------------+-------------------------+----------------+------------------+----------+ | 20:45:15.77 (311.31569d) | +05:06:39.95 (5.11110d) | 11.51 +/- 0.06 | q > 15.79 | 23:59:19 | +---------------------------+-------------------------+----------------+------------------+----------+ | 20:49:24.58 (312.35241d) | +01:56:09.64 (1.93601d) | 17.52 +/- 0.07 | q > 18.77 | 23:44:42 | +---------------------------+-------------------------+----------------+------------------+----------+ These positions are calibrated against Gaia DR2 with a positional uncertainty of 0.1" in each coordinate. We note that the first, bright candidate was identified in an image in which the sources are trailed. However, human inspection confirms that the source is not an artefact. The position of both transients is within the 50% probability region of the GBM error box, and no objects consistent with these positions and observing times were found in the Minor Planet Centre database. We also note that no underlying source is visible in archival PanSTARRS images at these positions. We obtained further observations of the second, fainter source on the following night and obtained a 5-sigma limiting magnitude of q > 19.22 at the transient position, consistent with fading behaviour. Further follow-up observations are encouraged in order to determine if either of these sources is the afterglow of GRB 220810A. MeerLICHT is built and run by a consortium consisting of Radboud University, the University of Cape Town, the South African Astronomical Observatory, the University of Oxford, the University of Manchester and the University of Amsterdam. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32461 SUBJECT: GRB 220810A: Swift ToO observations DATE: 22/08/12 18:42:04 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 220810A. Automated analysis of the XRT data will be presented online at https://www.swift.ac.uk/ToO_GRBs/00021510 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: 32464 SUBJECT: GRB 220810A: Swift-XRT observations DATE: 22/08/13 09:28:21 GMT FROM: Phil Evans at U of Leicester J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the second optical afterglow candidate observed by MeerLICHT (de Wet et al. GCN Circ. 32460) of the Fermi/GBM detected burst GRB 220810A (Fermi GBM team, GCN 32455), collecting 4.9 ks of Photon Counting (PC) mode data between T0+156.3 ks and T0+180.2 ks. No X-ray sources have been detected consistent with being within 9.9 arcsec of the MeerLICHT optical afterglow candidate position. The 3-sigma upper limit in the field is 0.003 ct s^-1, corresponding to a 0.3-10 keV observed flux of 1.1e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/ToO_GRBs/00021510. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 32469 SUBJECT: GRB 220810A: Further Swift-XRT observations DATE: 22/08/14 08:30:56 GMT FROM: Paolo D'Avanzo at INAF-OAB J. D. Gropp (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB), T. Sbarrato (INAF-OAB), P. D'Avanzo (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the first optical afterglow candidate observed by MeerLICHT (de Wet et al. GCN Circ. 32460) of the Fermi/GBM detected burst GRB 220810A (Fermi GBM team, GCN 32455), collecting 2.0 ks of Photon Counting (PC) mode data between T0+202.1 ks and T0+208.1 ks. No X-ray sources have been detected at the MeerLICHT optical afterglow candidate position. The 3-sigma upper limit in the field is 0.006 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.2e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). This circular is an official product of the Swift-XRT team.