//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31951 SUBJECT: GRB 220426B: Fermi GBM Final Real-time Localization DATE: 22/04/26 07:20:50 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 07:10:36 UT on 26 Apr 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220426B (trigger 672649841.18156 / 220426299). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 138.4, Dec = -13.8 (J2000 degrees, equivalent to J2000 09h 13m, -13d 48'), with a statistical uncertainty of 5.2 degrees. The angle from the Fermi LAT boresight is 55.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220426299/quicklook/glg_skymap_all_bn220426299.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/bn220426299/quicklook/glg_healpix_all_bn220426299.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220426299/quicklook/glg_lc_medres34_bn220426299.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31952 SUBJECT: Fermi GRB 220426B: Global MASTER-Net observations report DATE: 22/04/26 07:30:38 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-OAGH robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Mexico (OAGH National Institute for Astrophysics, Optics and Electronics) started inspect of the Fermi GRB 220426B ( Fermi GBM team, GCN 31951) errorbox 57 sec after notice time and 86 sec after trigger time at 2022-04-26 07:12:02 UT, with upper limit up to 17.6 mag. The observations began at zenith distance = 85 deg. The sun altitude is -45.5 deg. The galactic latitude b = 24 deg., longitude l = 244 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1954626 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 97 | 2022-04-26 07:12:02 | MASTER-OAGH | (09h 02m 58.79s , -12d 12m 15.5s) | C | 20 | 16.2 | 97 | 2022-04-26 07:12:02 | MASTER-OAGH | (09h 02m 14.28s , -11d 43m 39.5s) | C | 20 | 16.8 | 138 | 2022-04-26 07:12:43 | MASTER-OAGH | (09h 02m 51.98s , -12d 13m 13.9s) | C | 20 | 16.1 | 138 | 2022-04-26 07:12:43 | MASTER-OAGH | (09h 02m 07.29s , -11d 44m 42.8s) | C | 20 | 16.9 | 184 | 2022-04-26 07:13:24 | MASTER-OAGH | (09h 02m 58.07s , -12d 12m 47.9s) | C | 30 | 16.3 | 184 | 2022-04-26 07:13:24 | MASTER-OAGH | (09h 02m 13.27s , -11d 44m 16.4s) | C | 30 | 17.0 | 240 | 2022-04-26 07:14:16 | MASTER-OAGH | (09h 02m 55.13s , -12d 11m 21.0s) | C | 40 | 16.5 | 240 | 2022-04-26 07:14:16 | MASTER-OAGH | (09h 02m 10.21s , -11d 42m 49.2s) | C | 40 | 17.3 | 306 | 2022-04-26 07:15:17 | MASTER-OAGH | (09h 02m 55.31s , -12d 13m 04.4s) | C | 50 | 16.6 | 306 | 2022-04-26 07:15:17 | MASTER-OAGH | (09h 02m 10.34s , -11d 44m 31.5s) | C | 50 | 17.3 | 387 | 2022-04-26 07:16:28 | MASTER-OAGH | (09h 02m 58.55s , -12d 11m 44.0s) | C | 70 | 16.7 | 387 | 2022-04-26 07:16:28 | MASTER-OAGH | (09h 02m 13.45s , -11d 43m 10.6s) | C | 70 | 17.4 | 642 | 2022-04-26 07:20:18 | MASTER-OAGH | (09h 14m 16.17s , -13d 48m 19.4s) | C | 120 | 16.9 | 642 | 2022-04-26 07:20:18 | MASTER-OAGH | (09h 13m 31.04s , -13d 19m 47.7s) | C | 120 | 17.5 | 793 | 2022-04-26 07:22:39 | MASTER-OAGH | (09h 13m 24.36s , -13d 20m 51.6s) | C | 140 | 17.6 | 793 | 2022-04-26 07:22:39 | MASTER-OAGH | (09h 14m 09.78s , -13d 49m 20.3s) | C | 140 | 16.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.