TITLE: GCN CIRCULAR NUMBER: 30899 SUBJECT: Fermi trigger No 654658271: Global MASTER-Net observations report DATE: 21/09/30 09:15:27 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-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 GRB210930.06 (trigger No 654658271,19h 36m 40.08s , +24d 09m 00.0s, R=32.42) errorbox 491 sec after notice time and 615 sec after trigger time at 2021-09-30 01:41:21 UT, with upper limit up to 17.3 mag. The observations began at zenith distance = 68 deg. The sun altitude is -38.5 deg. The galactic latitude b = 1 deg., longitude l = 60 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1737652 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 646 | 2021-09-30 01:41:21 | MASTER-OAFA | (17h 45m 09.94s , +06d 12m 55.8s) | C | 60 | 16.4 | 731 | 2021-09-30 01:42:47 | MASTER-OAFA | (17h 53m 13.64s , +06d 11m 15.5s) | C | 60 | 17.3 | 970 | 2021-09-30 01:46:45 | MASTER-OAFA | (17h 34m 37.80s , +08d 05m 27.0s) | C | 60 | 15.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.