TITLE: GCN CIRCULAR NUMBER: 30428 SUBJECT: Fermi GRB 210709A: Global MASTER-Net observations report DATE: 21/07/09 06:00:08 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-IAC robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 210709A ( Fermi GBM team, GCN 30427) errorbox 121 sec after notice time and 150 sec after trigger time at 2021-07-09 04:51:34 UT, with upper limit up to 16.2 mag. Observations started at twilight. The observations began at zenith distance = 85 deg. The sun altitude is -16.2 deg. MASTER-OAFA robotic telescope located in Argentina (OAFA observatory of San Juan National University) started inspect of the Fermi GRB 210709A errorbox 162 sec after notice time and 191 sec after trigger time at 2021-07-09 04:52:15 UT, with upper limit up to 18.9 mag. The observations began at zenith distance = 15 deg. The sun altitude is -80.9 deg. The galactic latitude b = -28 deg., longitude l = 355 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1656291 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 165 | 2021-07-09 04:51:34 | MASTER-IAC | (19h 53m 28.95s , -45d 39m 58.5s) | P| | 30 | 16.0 | 165 | 2021-07-09 04:51:34 | MASTER-IAC | (19h 52m 20.20s , -45d 33m 36.3s) | P- | 30 | 15.0 | 206 | 2021-07-09 04:52:15 | MASTER-OAFA | (19h 50m 50.37s , -44d 56m 51.2s) | C | 30 | 17.8 | 220 | 2021-07-09 04:52:24 | MASTER-IAC | (19h 53m 28.65s , -45d 38m 59.8s) | P| | 40 | 16.0 | 220 | 2021-07-09 04:52:24 | MASTER-IAC | (19h 52m 19.93s , -45d 32m 38.3s) | P- | 40 | 15.2 | 261 | 2021-07-09 04:53:04 | MASTER-OAFA | (19h 50m 47.04s , -44d 55m 48.4s) | C | 40 | 18.1 | 285 | 2021-07-09 04:53:24 | MASTER-IAC | (19h 53m 35.38s , -45d 40m 01.8s) | P| | 50 | 16.2 | 285 | 2021-07-09 04:53:24 | MASTER-IAC | (19h 52m 26.65s , -45d 33m 40.9s) | P- | 50 | 15.1 | 325 | 2021-07-09 04:54:04 | MASTER-OAFA | (19h 50m 46.92s , -44d 57m 13.3s) | C | 50 | 18.2 | 360 | 2021-07-09 04:54:34 | MASTER-IAC | (19h 53m 29.54s , -45d 41m 03.4s) | P| | 60 | 16.2 | 360 | 2021-07-09 04:54:34 | MASTER-IAC | (19h 52m 20.76s , -45d 34m 42.9s) | P- | 60 | 15.2 | 400 | 2021-07-09 04:55:14 | MASTER-OAFA | (19h 50m 50.12s , -44d 55m 29.0s) | C | 60 | 18.4 | 637 | 2021-07-09 04:58:40 | MASTER-IAC | (19h 39m 58.96s , -44d 16m 07.4s) | P| | 120 | 15.8 | 637 | 2021-07-09 04:58:40 | MASTER-IAC | (19h 38m 52.40s , -44d 09m 49.2s) | P- | 120 | 13.6 | 684 | 2021-07-09 04:59:28 | MASTER-OAFA | (19h 37m 03.50s , -43d 35m 29.7s) | C | 120 | 18.6 | 834 | 2021-07-09 05:01:48 | MASTER-OAFA | (19h 37m 10.23s , -43d 35m 29.7s) | C | 140 | 18.8 | 962 | 2021-07-09 05:03:40 | MASTER-IAC | (19h 39m 48.98s , -44d 16m 42.0s) | P| | 170 | 14.9 | 1009 | 2021-07-09 05:04:28 | MASTER-OAFA | (19h 37m 06.16s , -43d 34m 06.7s) | C | 170 | 18.9 | 1204 | 2021-07-09 05:07:37 | MASTER-OAFA | (19h 37m 06.08s , -43d 35m 44.2s) | C | 180 | 18.9 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.