TITLE: GCN CIRCULAR NUMBER: 30800 SUBJECT: Fermi trigger No 652981861: Global MASTER-Net observations report DATE: 21/09/10 16:30:36 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> 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-Kislovodsk robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB210910.66 (trigger No 652981861,19h 50m 36.00s , +08d 45m 00.0s, R=5.4) errorbox 1717 sec after notice time and 1755 sec after trigger time at 2021-09-10 16:20:11 UT, with upper limit up to 17.0 mag. Observations started at twilight. The observations began at zenith distance = 38 deg. The sun altitude is -9.8 deg. The galactic latitude b = -9 deg., longitude l = 48 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1716539 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 1785 | 2021-09-10 16:20:11 | MASTER-Kislovodsk | (19h 43m 04.74s , +08d 58m 41.6s) | C | 60 | 15.6 | 1785 | 2021-09-10 16:20:11 | MASTER-Kislovodsk | (19h 47m 34.00s , +08d 33m 50.5s) | C | 60 | 16.4 | 1865 | 2021-09-10 16:21:31 | MASTER-Kislovodsk | (19h 49m 58.37s , +10d 51m 32.6s) | C | 60 | 15.8 | 1865 | 2021-09-10 16:21:31 | MASTER-Kislovodsk | (19h 54m 29.27s , +10d 26m 44.5s) | C | 60 | 16.7 | 1945 | 2021-09-10 16:22:51 | MASTER-Kislovodsk | (19h 52m 58.65s , +07d 02m 33.5s) | C | 60 | 15.8 | 1945 | 2021-09-10 16:22:51 | MASTER-Kislovodsk | (19h 57m 25.85s , +06d 37m 37.0s) | C | 60 | 16.7 | 2025 | 2021-09-10 16:24:12 | MASTER-Kislovodsk | (19h 58m 33.52s , +08d 56m 30.9s) | C | 60 | 16.0 | 2025 | 2021-09-10 16:24:12 | MASTER-Kislovodsk | (20h 03m 02.11s , +08d 31m 37.0s) | C | 60 | 17.0 | 2105 | 2021-09-10 16:25:32 | MASTER-Kislovodsk | (19h 37m 42.96s , +07d 04m 29.7s) | C | 60 | 15.8 | 2105 | 2021-09-10 16:25:32 | MASTER-Kislovodsk | (19h 42m 10.56s , +06d 39m 34.2s) | C | 60 | 16.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.