TITLE: GCN CIRCULAR NUMBER: 30735 SUBJECT: Fermi GRB 210827B: Global MASTER-Net observations report DATE: 21/08/28 12:30:29 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 GRB 210827B ( Fermi GBM team, GCN 30726) errorbox 24325 sec after notice time and 24337 sec after trigger time at 2021-08-27 16:55:53 UT, with upper limit up to 18.2 mag. Observations started at twilight. The observations began at zenith distance = 69 deg. The sun altitude is -11.4 deg. The galactic latitude b = -32 deg., longitude l = 26 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1701427 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 15633 | 2021-08-27 14:30:38 | MASTER- | (20h 28m 55.00s , -19d 15m 45.0s) | C | 20 | 15.2 | 16581 | 2021-08-27 14:46:27 | MASTER- | (20h 28m 52.92s , -19d 12m 38.6s) | C | 20 | 14.9 | 17531 | 2021-08-27 15:02:16 | MASTER- | (20h 28m 53.96s , -19d 13m 34.5s) | C | 20 | 15.0 | 18829 | 2021-08-27 15:23:55 | MASTER- | (20h 31m 16.41s , -17d 19m 29.2s) | C | 20 | 14.8 | 18829 | 2021-08-27 15:23:55 | MASTER- | (20h 23m 01.74s , -18d 44m 06.1s) | C | 20 | 13.7 | 19755 | 2021-08-27 15:39:20 | MASTER- | (20h 31m 06.85s , -17d 19m 50.6s) | C | 20 | 12.6 | 19755 | 2021-08-27 15:39:20 | MASTER- | (20h 22m 54.22s , -18d 43m 23.5s) | C | 20 | 13.5 | 20653 | 2021-08-27 15:54:19 | MASTER- | (20h 31m 05.17s , -17d 20m 21.3s) | C | 20 | 14.9 | 20653 | 2021-08-27 15:54:19 | MASTER- | (20h 22m 55.05s , -18d 42m 04.8s) | C | 20 | 13.2 | 24368 | 2021-08-27 16:55:53 | MASTER-Kislovodsk | (20h 27m 37.06s , -17d 37m 30.7s) | C | 60 | 16.9 | 24368 | 2021-08-27 16:55:53 | MASTER-Kislovodsk | (20h 32m 08.17s , -18d 03m 02.3s) | C | 60 | 17.1 | 24528 | 2021-08-27 16:58:34 | MASTER-Kislovodsk | (20h 25m 24.24s , -19d 31m 47.6s) | C | 60 | 17.0 | 24528 | 2021-08-27 16:58:34 | MASTER-Kislovodsk | (20h 29m 57.78s , -19d 57m 21.8s) | C | 60 | 17.4 | 25329 | 2021-08-27 17:11:55 | MASTER-Kislovodsk | (20h 27m 35.57s , -17d 37m 16.0s) | C | 60 | 17.3 | 25329 | 2021-08-27 17:11:55 | MASTER-Kislovodsk | (20h 32m 08.08s , -18d 02m 47.5s) | C | 60 | 17.9 | 25489 | 2021-08-27 17:14:35 | MASTER-Kislovodsk | (20h 25m 19.62s , -19d 33m 12.5s) | C | 60 | 17.3 | 25489 | 2021-08-27 17:14:35 | MASTER-Kislovodsk | (20h 29m 54.59s , -19d 58m 46.9s) | C | 60 | 17.9 | 26292 | 2021-08-27 17:27:57 | MASTER-Kislovodsk | (20h 27m 38.37s , -17d 37m 26.2s) | C | 60 | 17.4 | 26292 | 2021-08-27 17:27:57 | MASTER-Kislovodsk | (20h 32m 11.64s , -18d 02m 59.8s) | C | 60 | 18.2 | 26452 | 2021-08-27 17:30:37 | MASTER-Kislovodsk | (20h 25m 25.65s , -19d 31m 23.4s) | C | 60 | 17.5 | 26452 | 2021-08-27 17:30:37 | MASTER-Kislovodsk | (20h 30m 01.38s , -19d 56m 58.4s) | C | 60 | 18.1 | 27014 | 2021-08-27 17:39:59 | MASTER-Kislovodsk | (20h 31m 11.23s , -15d 44m 54.0s) | C | 60 | 17.5 | 27014 | 2021-08-27 17:39:59 | MASTER-Kislovodsk | (20h 35m 43.24s , -16d 10m 21.8s) | C | 60 | 18.2 | 27174 | 2021-08-27 17:42:40 | MASTER-Kislovodsk | (20h 24m 24.36s , -21d 25m 55.7s) | C | 60 | 17.5 | 27174 | 2021-08-27 17:42:40 | MASTER-Kislovodsk | (20h 29m 03.61s , -21d 51m 33.9s) | C | 60 | 18.1 | 27575 | 2021-08-27 17:49:20 | MASTER-Kislovodsk | (20h 41m 31.97s , -19d 31m 13.5s) | C | 60 | 17.5 | 27575 | 2021-08-27 17:49:20 | MASTER-Kislovodsk | (20h 46m 07.89s , -19d 56m 48.7s) | C | 60 | 18.2 | 27816 | 2021-08-27 17:53:21 | MASTER-Kislovodsk | (20h 43m 33.76s , -17d 38m 08.2s) | C | 60 | 17.5 | 27816 | 2021-08-27 17:53:21 | MASTER-Kislovodsk | (20h 48m 07.55s , -18d 03m 38.8s) | C | 60 | 18.1 | 27976 | 2021-08-27 17:56:02 | MASTER-Kislovodsk | (20h 31m 16.12s , -15d 44m 00.6s) | C | 60 | 17.6 | 27976 | 2021-08-27 17:56:02 | MASTER-Kislovodsk | (20h 35m 48.31s , -16d 09m 26.7s) | C | 60 | 18.2 | 28137 | 2021-08-27 17:58:42 | MASTER-Kislovodsk | (20h 24m 31.19s , -21d 26m 25.0s) | C | 60 | 17.5 | 28137 | 2021-08-27 17:58:43 | MASTER-Kislovodsk | (20h 29m 10.79s , -21d 52m 01.6s) | C | 60 | 18.2 | 28537 | 2021-08-27 18:05:23 | MASTER-Kislovodsk | (20h 46m 07.24s , -19d 56m 31.8s) | C | 60 | 18.0 | 28537 | 2021-08-27 18:05:23 | MASTER-Kislovodsk | (20h 41m 30.66s , -19d 30m 59.4s) | C | 60 | 17.4 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.