//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31914 SUBJECT: GRB 220418A: Fermi GBM Final Real-time Localization DATE: 22/04/18 16:03:22 GMT FROM: Fermi GBM Team at MSFC/Fermi-GBM The Fermi GBM team reports the detection of a likely LONG GRB At 15:51:58 UT on 18 Apr 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220418A (trigger 671989923.878466 / 220418661). The on-ground calculated location, using the Fermi GBM trigger data, is RA = 334.3, Dec = 62.0 (J2000 degrees, equivalent to J2000 22h 17m, 62d 00'), with a statistical uncertainty of 7.8 degrees. The angle from the Fermi LAT boresight is 18.0 degrees. The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220418661/quicklook/glg_skymap_all_bn220418661.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/bn220418661/quicklook/glg_healpix_all_bn220418661.fit The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220418661/quicklook/glg_lc_medres34_bn220418661.gif //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 31916 SUBJECT: Fermi GRB 220418A: Global MASTER-Net observations report DATE: 22/04/18 18:15:38 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 220418A ( Fermi GBM team, GCN 31914) errorbox 7665 sec after notice time and 7697 sec after trigger time at 2022-04-18 18:00:16 UT, with upper limit up to 13.9 mag. The observations began at zenith distance = 75 deg. The sun altitude is -20.9 deg. The galactic latitude b = 4 deg., longitude l = 106 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1946689 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 7727 | 2022-04-18 18:00:16 | MASTER-Kislovodsk | (22h 05m 59.24s , +61d 57m 24.4s) | C | 60 | 13.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.