TITLE: GCN CIRCULAR NUMBER: 31168 SUBJECT: Fermi GRB 211204A: Global MASTER-Net observations report DATE: 21/12/04 03:45:06 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), 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 211204A ( Fermi GBM team, GCN 31167) errorbox 425 sec after notice time and 452 sec after trigger time at 2021-12-04 03:35:08 UT, with upper limit up to 18.4 mag. The observations began at zenith distance = 32 deg. The sun altitude is -35.5 deg. The galactic latitude b = -62 deg., longitude l = 270 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1803448 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 482 | 2021-12-04 03:35:08 | MASTER-OAFA | (02h 22m 56.00s , -59d 01m 07.3s) | C | 60 | 18.3 | 562 | 2021-12-04 03:36:28 | MASTER-OAFA | (02h 38m 43.63s , -58d 58m 59.5s) | C | 60 | 18.2 | 642 | 2021-12-04 03:37:48 | MASTER-OAFA | (02h 16m 25.09s , -49d 29m 44.3s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.