TITLE: GCN CIRCULAR NUMBER: 31172 SUBJECT: Fermi GRB 211204C: Global MASTER-Net observations report DATE: 21/12/04 22:00:08 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-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 211204C ( Fermi GBM team, GCN 31171) errorbox 113 sec after notice time and 142 sec after trigger time at 2021-12-04 21:39:22 UT, with upper limit up to 17.9 mag. The observations began at zenith distance = 36 deg. The sun altitude is -46.1 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 211204C errorbox 592 sec after notice time and 621 sec after trigger time at 2021-12-04 21:47:21 UT, with upper limit up to 13.2 mag. The observations began at zenith distance = 59 deg. The sun altitude is -67.2 deg. The galactic latitude b = -4 deg., longitude l = 109 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1804120 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 157 | 2021-12-04 21:39:22 | MASTER-IAC | (23h 28m 59.46s , +57d 30m 33.7s) | P| | 30 | 16.9 | 202 | 2021-12-04 21:39:22 | MASTER-IAC | (23h 28m 59.46s , +57d 30m 33.7s) | P| | 120 | 17.7 | Coadd 212 | 2021-12-04 21:40:12 | MASTER-IAC | (23h 28m 51.98s , +57d 29m 37.7s) | P| | 40 | 17.2 | 277 | 2021-12-04 21:41:12 | MASTER-IAC | (23h 28m 57.77s , +57d 29m 49.8s) | P| | 50 | 17.3 | 352 | 2021-12-04 21:42:22 | MASTER-IAC | (23h 28m 54.98s , +57d 31m 18.2s) | P| | 60 | 17.4 | 641 | 2021-12-04 21:46:41 | MASTER-IAC | (23h 02m 55.70s , +55d 44m 36.6s) | P| | 120 | 17.7 | 641 | 2021-12-04 21:46:41 | MASTER-IAC | (23h 04m 33.66s , +55d 38m 30.9s) | P- | 120 | 16.5 | 681 | 2021-12-04 21:47:21 | MASTER-Kislovodsk | (23h 05m 40.54s , +55d 45m 23.3s) | P- | 120 | 12.3 | 846 | 2021-12-04 21:47:21 | MASTER-Kislovodsk | (23h 05m 40.54s , +55d 45m 23.3s) | P- | 450 | 12.3 | Coadd 791 | 2021-12-04 21:49:01 | MASTER-IAC | (23h 02m 50.22s , +55d 44m 07.7s) | P| | 140 | 17.8 | 791 | 2021-12-04 21:49:01 | MASTER-IAC | (23h 04m 28.38s , +55d 38m 01.6s) | P- | 140 | 16.7 | 837 | 2021-12-04 21:49:42 | MASTER-Kislovodsk | (23h 05m 37.26s , +55d 46m 40.5s) | P- | 150 | 12.4 | 966 | 2021-12-04 21:51:41 | MASTER-IAC | (23h 02m 49.52s , +55d 45m 09.1s) | P| | 170 | 17.9 | 966 | 2021-12-04 21:51:41 | MASTER-IAC | (23h 04m 27.93s , +55d 39m 02.5s) | P- | 170 | 16.9 | 1022 | 2021-12-04 21:52:32 | MASTER-Kislovodsk | (23h 05m 37.19s , +55d 45m 32.4s) | P- | 180 | 13.2 | The observation and reduction will continue. The message may be cited.