TITLE: GCN CIRCULAR NUMBER: 31691 SUBJECT: Fermi GRB 220305A: Global MASTER-Net observations report DATE: 22/03/06 04:15:27 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, T.Pogrosheva, E.Minkina, A.Chasovnikov, V.Topolev, V.Grinshpun, D.Kuvshinov, D. Cheryasov (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), B.L.Carrasco, J.R.Valdes,V.Chavushyan, C.J.Martinez, V.M.Patino Alvarez, M.L.H.Rodriguez (INAOE, OAGH) A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 220305A ( R. Dunwoody et al., GCN 31689) errorbox 56245 sec after notice time and 56274 sec after trigger time at 2022-03-06 03:11:15 UT, with upper limit up to 18.3 mag. The observations began at zenith distance = 25 deg. The sun altitude is -46.7 deg. The galactic latitude b = 26 deg., longitude l = 287 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1902853 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 56305 | 2022-03-06 03:11:15 | MASTER-OAFA | (11h 29m 45.56s , -35d 27m 42.1s) | C | 60 | 15.9 | 58403 | 2022-03-06 03:46:13 | MASTER-OAFA | (11h 29m 45.60s , -35d 28m 47.3s) | C | 60 | 18.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.