//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31818 SUBJECT: GRB 220403A: Fermi GBM Final Real-time Localization DATE: 22/04/03 10:21:18 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 10:10:02 UT on 3 Apr 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220403A (trigger 670673407.661128 / 220403424). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 56.5, Dec = -44.3 (J2000 degrees, equivalent to J2000 03h 46m, -44d 17'), with a statistical uncertainty of 15.3 degrees. The angle from the Fermi LAT boresight is 14.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220403424/quicklook/glg_skymap_all_bn220403424.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/bn220403424/quicklook/glg_healpix_all_bn220403424.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220403424/quicklook/glg_lc_medres34_bn220403424.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31819 SUBJECT: Fermi GRB 220403A: Global MASTER-Net observations report DATE: 22/04/03 20:30:33 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 220403A ( Fermi GBM team, GCN 31818) errorbox 25928 sec after notice time and 25957 sec after trigger time at 2022-04-03 17:22:40 UT, with upper limit up to 19.0 mag. Observations started at twilight. The observations began at zenith distance = 40 deg. The sun altitude is -11.4 deg. The galactic latitude b = -51 deg., longitude l = 251 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1931107 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 25988 | 2022-04-03 17:22:40 | MASTER-SAAO | (04h 20m 06.06s , -55d 00m 19.5s) | V | 60 | 17.1 | 26067 | 2022-04-03 17:23:59 | MASTER-SAAO | (04h 20m 11.62s , -55d 00m 16.9s) | C | 60 | 17.3 | 26931 | 2022-04-03 17:38:24 | MASTER-SAAO | (04h 20m 10.16s , -54d 59m 21.9s) | V | 60 | 17.2 | 27011 | 2022-04-03 17:39:44 | MASTER-SAAO | (04h 20m 13.25s , -54d 58m 04.9s) | C | 60 | 17.7 | 32778 | 2022-04-03 19:15:50 | MASTER-SAAO | (04h 16m 32.90s , -29d 11m 52.6s) | C | 60 | 18.4 | 32858 | 2022-04-03 19:17:10 | MASTER-SAAO | (04h 25m 45.28s , -29d 10m 01.4s) | C | 60 | 19.0 | 33896 | 2022-04-03 19:34:28 | MASTER-SAAO | (04h 16m 37.18s , -29d 11m 05.9s) | C | 60 | 18.0 | 33976 | 2022-04-03 19:35:48 | MASTER-SAAO | (04h 25m 49.01s , -29d 09m 49.4s) | C | 60 | 18.5 | 34928 | 2022-04-03 19:51:41 | MASTER-SAAO | (04h 16m 45.67s , -29d 10m 04.1s) | C | 60 | 17.5 | 35008 | 2022-04-03 19:53:00 | MASTER-SAAO | (04h 25m 46.29s , -29d 10m 59.4s) | C | 60 | 18.1 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31822 SUBJECT: GRB 220403A: Tautenburg observations DATE: 22/04/03 22:57:37 GMT FROM: Ana Nicuesa at TLS Tautenburg A. Nicuesa Guelbenzu, B. Stecklum, S. Klose, S. Melnikov, and U. Ludwig (all Tautenburg) report: Tautenburg started observing the field of GRB 220403A (Klingler et al. GCN 31820) at 2022-04-03, 21:35:37 UT, using the 1.34m Schmidt telescope equipped with the TAUKAM 6k x 6k CCD camera. Observations are still ongoing. At a mean time 21:36:07 UT for the optical transient discovered by Swift/UVOT, we measure the following magnitude: r = 19.28 +/- 0.04 mag (AB), calibrated against the Pan-STARRS catalog. Compared to the observations reported by Jelinek et al. (GCN 31821), the source is fading.