TITLE: GCN CIRCULAR NUMBER: 30801 SUBJECT: Fermi trigger No 652944960: Global MASTER-Net observations report DATE: 21/09/10 16:45:20 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 GRB210910.23 (trigger No 652944960,20h 04m 52.80s , +25d 42m 36.0s, R=13.52) errorbox 38693 sec after notice time and 38736 sec after trigger time at 2021-09-10 16:21:31 UT, with upper limit up to 17.9 mag. Observations started at twilight. The observations began at zenith distance = 37 deg. The sun altitude is -10.0 deg. The galactic latitude b = -3 deg., longitude l = 64 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1716045 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 38766 | 2021-09-10 16:21:31 | MASTER-Kislovodsk | (19h 49m 58.37s , +10d 51m 32.6s) | C | 60 | 15.8 | 38766 | 2021-09-10 16:21:31 | MASTER-Kislovodsk | (19h 54m 29.27s , +10d 26m 44.5s) | C | 60 | 16.7 | 39167 | 2021-09-10 16:28:12 | MASTER-Kislovodsk | (19h 42m 34.95s , +12d 46m 23.7s) | C | 60 | 16.1 | 39167 | 2021-09-10 16:28:12 | MASTER-Kislovodsk | (19h 47m 08.01s , +12d 21m 42.0s) | C | 60 | 17.0 | 39408 | 2021-09-10 16:32:13 | MASTER-Kislovodsk | (19h 58m 09.20s , +12d 45m 21.7s) | C | 60 | 16.9 | 39408 | 2021-09-10 16:32:13 | MASTER-Kislovodsk | (20h 02m 41.75s , +12d 20m 37.5s) | C | 60 | 17.8 | 39488 | 2021-09-10 16:33:33 | MASTER-Kislovodsk | (20h 09m 50.61s , +10d 25m 29.7s) | C | 60 | 17.8 | 39488 | 2021-09-10 16:33:33 | MASTER-Kislovodsk | (20h 05m 20.49s , +10d 50m 19.2s) | C | 60 | 16.8 | 39728 | 2021-09-10 16:37:33 | MASTER-Kislovodsk | (19h 49m 54.56s , +10d 50m 54.3s) | C | 60 | 17.0 | 39728 | 2021-09-10 16:37:33 | MASTER-Kislovodsk | (19h 54m 25.09s , +10d 26m 09.6s) | C | 60 | 17.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.