TITLE: GCN CIRCULAR NUMBER: 29267 SUBJECT: Fermi trigger No 631584650: Global MASTER-Net observations report DATE: 21/01/06 03:15:18 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, 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, O.Ershova (Irkutsk State University, API), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), V. Yurkov, A. Gabovich, Yu. Sergienko (Blagoveschensk Educational State University) MASTER-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB210106.01 (trigger No 631584650,16h 39m 24.00s , -11d 58m 58.8s, R=32.98) errorbox 6552 sec after notice time and 6625 sec after trigger time at 2021-01-06 02:01:10 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 68 deg. The sun altitude is -34.5 deg. The galactic latitude b = 22 deg., longitude l = 6 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1520158 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 6655 | 2021-01-06 02:01:10 | MASTER-Tavrida | (16h 26m 41.95s , +18d 14m 22.9s) | C | 60 | 16.9 | 6734 | 2021-01-06 02:02:29 | MASTER-Tavrida | (15h 59m 21.83s , +12d 14m 35.1s) | C | 60 | 16.4 | 8804 | 2021-01-06 02:36:59 | MASTER-Tavrida | (16h 16m 07.51s , +16d 15m 35.8s) | C | 60 | 18.3 | 8804 | 2021-01-06 02:36:59 | MASTER-Tavrida | (16h 22m 18.47s , +16d 12m 44.9s) | C | 60 | 17.3 | 8884 | 2021-01-06 02:38:19 | MASTER-Tavrida | (16h 26m 46.30s , +18d 14m 07.5s) | C | 60 | 18.1 | 8884 | 2021-01-06 02:38:19 | MASTER-Tavrida | (16h 33m 01.19s , +18d 11m 16.2s) | C | 60 | 17.2 | 8963 | 2021-01-06 02:39:38 | MASTER-Tavrida | (15h 59m 12.94s , +12d 14m 15.0s) | C | 60 | 18.2 | 8964 | 2021-01-06 02:39:38 | MASTER-Tavrida | (16h 05m 17.40s , +12d 11m 23.4s) | C | 60 | 17.3 | 9043 | 2021-01-06 02:40:58 | MASTER-Tavrida | (16h 38m 43.19s , +20d 13m 02.8s) | C | 60 | 18.0 | 9043 | 2021-01-06 02:40:58 | MASTER-Tavrida | (16h 45m 02.60s , +20d 10m 10.6s) | C | 60 | 17.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.