TITLE: GCN CIRCULAR NUMBER: 30307 SUBJECT: Fermi GRB 210622B: Global MASTER-Net observations report DATE: 21/06/22 23:17:27 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 GRB 210622B ( Fermi GBM team, GCN 30298) errorbox 43469 sec after notice time and 43496 sec after trigger time at 2021-06-22 22:37:57 UT, with upper limit up to 17.8 mag. Observations started at twilight. The observations began at zenith distance = 56 deg. The sun altitude is -12.0 deg. The galactic latitude b = 15 deg., longitude l = 237 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1642370 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 43526 | 2021-06-22 22:37:57 | MASTER-OAFA | (08h 14m 05.24s , -14d 37m 45.1s) | C | 60 | 17.4 | 43605 | 2021-06-22 22:39:17 | MASTER-OAFA | (08h 22m 14.70s , -14d 38m 34.0s) | C | 60 | 17.4 | 43685 | 2021-06-22 22:40:36 | MASTER-OAFA | (08h 25m 46.77s , -12d 42m 57.2s) | C | 60 | 17.6 | 43767 | 2021-06-22 22:41:58 | MASTER-OAFA | (08h 33m 57.71s , -12d 44m 12.9s) | C | 60 | 17.8 | 43847 | 2021-06-22 22:43:18 | MASTER-OAFA | (08h 10m 11.95s , -12d 43m 46.8s) | C | 60 | 17.8 | 43926 | 2021-06-22 22:44:37 | MASTER-OAFA | (08h 18m 21.69s , -12d 42m 35.5s) | C | 60 | 17.8 | 44006 | 2021-06-22 22:45:57 | MASTER-OAFA | (08h 29m 39.40s , -14d 38m 20.6s) | C | 60 | 17.6 | 44085 | 2021-06-22 22:47:17 | MASTER-OAFA | (08h 38m 00.16s , -14d 38m 01.8s) | C | 60 | 17.8 | 44165 | 2021-06-22 22:48:36 | MASTER-OAFA | (08h 18m 29.20s , -16d 32m 12.2s) | C | 60 | 17.7 | 44244 | 2021-06-22 22:49:56 | MASTER-OAFA | (08h 26m 51.96s , -16d 30m 43.5s) | C | 60 | 17.6 | 44783 | 2021-06-22 22:58:54 | MASTER-OAFA | (08h 14m 00.60s , -14d 36m 33.1s) | C | 60 | 17.8 | 44862 | 2021-06-22 23:00:14 | MASTER-OAFA | (08h 22m 20.98s , -14d 37m 22.9s) | C | 60 | 17.7 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.