TITLE: GCN CIRCULAR NUMBER: 28488 SUBJECT: Fermi GRB 200923A: Global MASTER-Net observations report DATE: 20/09/24 03:15:27 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 200923A ( Fermi GBM team, GCN 28486) errorbox 19833 sec after notice time and 19860 sec after trigger time at 2020-09-23 23:28:43 UT, with upper limit up to 15.7 mag. Observations started at twilight. The observations began at zenith distance = 81 deg. The sun altitude is -13.0 deg. The galactic latitude b = -9 deg., longitude l = 270 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1447664 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 19890 | 2020-09-23 23:28:43 | MASTER-OAFA | (08h 21m 14.47s , -67d 19m 15.6s) | C | 60 | 13.2 | 20169 | 2020-09-23 23:33:22 | MASTER-OAFA | (09h 03m 53.41s , -67d 17m 40.0s) | C | 60 | 14.5 | 20735 | 2020-09-23 23:42:48 | MASTER-OAFA | (08h 42m 35.32s , -67d 19m 14.3s) | C | 60 | 14.5 | 30169 | 2020-09-24 02:20:02 | MASTER-OAFA | (07h 41m 44.86s , -66d 39m 20.2s) | C | 60 | 15.7 | 30466 | 2020-09-24 02:24:59 | MASTER-OAFA | (07h 08m 15.95s , -63d 18m 27.3s) | C | 60 | 15.2 | 30832 | 2020-09-24 02:31:06 | MASTER-OAFA | (07h 41m 46.93s , -65d 17m 08.2s) | C | 60 | 14.3 | 30926 | 2020-09-24 02:32:39 | MASTER-OAFA | (08h 01m 22.93s , -66d 39m 47.6s) | C | 60 | 14.4 | 31019 | 2020-09-24 02:34:12 | MASTER-OAFA | (07h 08m 22.08s , -63d 18m 00.7s) | C | 60 | 14.1 | 31110 | 2020-09-24 02:35:43 | MASTER-OAFA | (07h 26m 40.63s , -64d 38m 46.6s) | C | 60 | 13.0 | 31766 | 2020-09-24 02:46:39 | MASTER-OAFA | (08h 01m 25.36s , -65d 17m 24.8s) | C | 60 | 14.0 | 31858 | 2020-09-24 02:48:12 | MASTER-OAFA | (07h 26m 40.84s , -64d 38m 47.1s) | C | 60 | 14.4 | 31954 | 2020-09-24 02:49:47 | MASTER-OAFA | (06h 56m 51.23s , -61d 17m 48.9s) | C | 60 | 13.6 | 32451 | 2020-09-24 02:58:04 | MASTER-OAFA | (07h 44m 51.93s , -64d 39m 59.0s) | C | 60 | 13.6 | 32544 | 2020-09-24 02:59:38 | MASTER-OAFA | (07h 13m 52.80s , -61d 15m 49.9s) | C | 60 | 13.4 | 32646 | 2020-09-24 03:01:19 | MASTER-OAFA | (08h 21m 06.58s , -66d 37m 21.4s) | C | 60 | 13.8 | 32742 | 2020-09-24 03:02:55 | MASTER-OAFA | (06h 54m 21.05s , -57d 15m 33.1s) | C | 60 | 12.9 | 32836 | 2020-09-24 03:04:29 | MASTER-OAFA | (07h 44m 58.07s , -64d 38m 59.6s) | C | 60 | 14.9 | 32934 | 2020-09-24 03:06:07 | MASTER-OAFA | (08h 02m 56.16s , -63d 17m 01.2s) | C | 60 | 13.7 | 33030 | 2020-09-24 03:07:43 | MASTER-OAFA | (07h 14m 07.48s , -62d 40m 29.8s) | C | 60 | 15.4 | 33122 | 2020-09-24 03:09:15 | MASTER-OAFA | (07h 30m 53.96s , -61d 15m 34.1s) | C | 60 | 14.3 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.