TITLE: GCN CIRCULAR NUMBER: 29317 SUBJECT: Fermi trigger No 632573937: Global MASTER-Net observations report DATE: 21/01/18 07:30:38 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-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 GRB210117.46 (trigger No 632573937,15h 07m 04.80s , -20d 13m 48.0s, R=1.91) errorbox 70520 sec after notice time and 70580 sec after trigger time at 2021-01-18 06:35:12 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 68 deg. The sun altitude is -32.1 deg. The galactic latitude b = 32 deg., longitude l = 342 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1528013 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 70611 | 2021-01-18 06:35:12 | MASTER-OAFA | (15h 00m 20.63s , -22d 36m 28.3s) | C | 60 | 18.4 | 70770 | 2021-01-18 06:37:51 | MASTER-OAFA | (14h 54m 35.90s , -18d 35m 58.9s) | C | 60 | 18.4 | 73053 | 2021-01-18 07:15:55 | MASTER-OAFA | (14h 56m 54.25s , -20d 36m 56.6s) | C | 60 | 18.5 | 73541 | 2021-01-18 07:24:02 | MASTER-OAFA | (15h 02m 58.03s , -18d 37m 34.8s) | C | 60 | 18.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.