TITLE: GCN CIRCULAR NUMBER: 29222 SUBJECT: Fermi GRB 210101A: Global MASTER-Net observations report DATE: 21/01/02 04:00:09 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 GRB 210101A ( Fermi GBM team, GCN 29215) errorbox 19545 sec after notice time and 19603 sec after trigger time at 2021-01-01 20:19:50 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 35 deg. The sun altitude is -62.4 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 210101A errorbox 38568 sec after notice time and 38626 sec after trigger time at 2021-01-02 01:36:52 UT, with upper limit up to 18.2 mag. The observations began at zenith distance = 36 deg. The sun altitude is -81.5 deg. The galactic latitude b = 42 deg., longitude l = 169 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1516794 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 19633 | 2021-01-01 20:19:50 | MASTER-Tavrida | (08h 53m 10.40s , +56d 17m 44.1s) | C | 60 | 18.0 | 19633 | 2021-01-01 20:19:50 | MASTER-Tavrida | (09h 03m 54.67s , +56d 15m 14.2s) | C | 60 | 18.2 | 20536 | 2021-01-01 20:34:53 | MASTER-Tavrida | (08h 53m 01.80s , +56d 17m 48.0s) | C | 60 | 18.2 | 20536 | 2021-01-01 20:34:53 | MASTER-Tavrida | (09h 03m 45.63s , +56d 15m 32.5s) | C | 60 | 18.1 | 38656 | 2021-01-02 01:36:52 | MASTER-IAC | (09h 23m 12.29s , +56d 10m 19.9s) | C | 60 | 18.2 | 43403 | 2021-01-02 02:56:00 | MASTER-Tavrida | (08h 44m 09.21s , +53d 57m 34.6s) | C | 60 | 18.0 | 43403 | 2021-01-02 02:56:00 | MASTER-Tavrida | (08h 33m 51.91s , +54d 00m 03.2s) | C | 60 | 17.7 | 44349 | 2021-01-02 03:11:45 | MASTER-Tavrida | (08h 44m 05.63s , +53d 56m 08.2s) | C | 60 | 18.0 | 44349 | 2021-01-02 03:11:45 | MASTER-Tavrida | (08h 33m 52.43s , +53d 58m 37.8s) | C | 60 | 18.0 | 45423 | 2021-01-02 03:29:40 | MASTER-Tavrida | (08h 44m 05.11s , +53d 57m 15.1s) | C | 60 | 18.0 | 45423 | 2021-01-02 03:29:40 | MASTER-Tavrida | (08h 33m 50.61s , +54d 00m 16.0s) | C | 60 | 18.0 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.