TITLE: GCN CIRCULAR NUMBER: 32566 SUBJECT: Fermi trigger No 685452089: Global MASTER-Net observations report DATE: 22/09/21 17:45:11 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko, G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin (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 (Irkutsk State University, API), L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational State University) MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB220921.47 (trigger No 685452089,06h 17m 19.20s , -80d 35m 23.6s, R=11.45) errorbox 21513 sec after notice time and 21548 sec after trigger time at 2022-09-21 17:20:32 UT, with upper limit up to 18.8 mag. Observations started at twilight. The observations began at zenith distance = 67 deg. The sun altitude is -10.6 deg. The galactic latitude b = -28 deg., longitude l = 292 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=2097261 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 21578 | 2022-09-21 17:20:32 | MASTER-SAAO | (05h 48m 00.96s , -80d 29m 29.1s) | C | 60 | 17.3 | 21670 | 2022-09-21 17:22:04 | MASTER-SAAO | (06h 36m 06.73s , -80d 27m 48.2s) | C | 60 | 17.3 | 21753 | 2022-09-21 17:23:27 | MASTER-SAAO | (06h 07m 05.30s , -78d 33m 36.9s) | C | 60 | 17.4 | 21843 | 2022-09-21 17:24:57 | MASTER-SAAO | (06h 47m 20.34s , -78d 33m 00.5s) | C | 60 | 17.5 | 21924 | 2022-09-21 17:26:18 | MASTER-SAAO | (05h 19m 37.33s , -82d 25m 03.2s) | C | 60 | 17.9 | 22018 | 2022-09-21 17:27:52 | MASTER-SAAO | (06h 19m 53.18s , -82d 20m 41.7s) | C | 60 | 18.0 | 22100 | 2022-09-21 17:29:14 | MASTER-SAAO | (07h 19m 14.95s , -80d 25m 31.5s) | C | 60 | 18.1 | 22194 | 2022-09-21 17:30:48 | MASTER-SAAO | (08h 01m 04.05s , -80d 23m 27.9s) | C | 60 | 18.2 | 22286 | 2022-09-21 17:32:20 | MASTER-SAAO | (07h 06m 06.46s , -82d 19m 59.5s) | C | 60 | 18.3 | 22367 | 2022-09-21 17:33:41 | MASTER-SAAO | (08h 05m 42.59s , -82d 15m 44.5s) | C | 60 | 18.5 | 22459 | 2022-09-21 17:35:13 | MASTER-SAAO | (04h 50m 18.91s , -78d 37m 56.5s) | C | 60 | 18.5 | 22541 | 2022-09-21 17:36:35 | MASTER-SAAO | (05h 30m 57.51s , -78d 36m 42.0s) | C | 60 | 18.5 | 22636 | 2022-09-21 17:38:10 | MASTER-SAAO | (05h 48m 03.53s , -80d 30m 45.1s) | C | 60 | 18.7 | 22716 | 2022-09-21 17:39:30 | MASTER-SAAO | (06h 36m 22.76s , -80d 28m 00.5s) | C | 60 | 18.8 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.