TITLE: GCN CIRCULAR NUMBER: 30641 SUBJECT: Fermi GRB 210813A: Global MASTER-Net observations report DATE: 21/08/13 02:15:19 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-Tavrida robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, SAI Crimea astronomical station) started inspect of the Fermi GRB 210813A ( Fermi GBM team, GCN 30640) errorbox 574 sec after notice time and 629 sec after trigger time at 2021-08-13 01:04:52 UT, with upper limit up to 16.5 mag. Observations started at twilight. The observations began at zenith distance = 36 deg. The sun altitude is -16.1 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) started inspect of the Fermi GRB 210813A errorbox 616 sec after notice time and 671 sec after trigger time at 2021-08-13 01:05:35 UT, with upper limit up to 19.8 mag. The observations began at zenith distance = 54 deg. The sun altitude is -47.3 deg. MASTER-Kislovodsk robotic telescope located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) started inspect of the Fermi GRB 210813A errorbox 626 sec after notice time and 681 sec after trigger time at 2021-08-13 01:05:44 UT, with upper limit up to 17.0 mag. Observations started at twilight. The observations began at zenith distance = 35 deg. The sun altitude is -11.9 deg. The galactic latitude b = -54 deg., longitude l = 128 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1688882 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 694 | 2021-08-13 01:04:52 | MASTER-Tavrida | (00h 56m 40.50s , +08d 15m 20.7s) | P\ | 130 | 16.1 | 737 | 2021-08-13 01:05:35 | MASTER-IAC | (00h 59m 18.91s , +07d 58m 47.0s) | P| | 130 | 18.6 | 907 | 2021-08-13 01:05:35 | MASTER-IAC | (00h 59m 18.91s , +07d 58m 47.0s) | P| | 470 | 19.7 | Coadd 737 | 2021-08-13 01:05:35 | MASTER-IAC | (00h 58m 31.40s , +08d 03m 43.9s) | P- | 130 | 18.4 | 907 | 2021-08-13 01:05:35 | MASTER-IAC | (00h 58m 31.40s , +08d 03m 44.0s) | P- | 470 | 19.3 | Coadd 746 | 2021-08-13 01:05:44 | MASTER-Kislovodsk | (01h 00m 05.80s , +08d 08m 53.0s) | P- | 130 | 15.9 | 916 | 2021-08-13 01:05:44 | MASTER-Kislovodsk | (01h 00m 05.81s , +08d 08m 53.0s) | P- | 470 | 16.7 | Coadd 746 | 2021-08-13 01:05:44 | MASTER-Kislovodsk | (01h 00m 01.56s , +08d 32m 50.9s) | P| | 130 | 16.5 | 916 | 2021-08-13 01:05:44 | MASTER-Kislovodsk | (01h 00m 01.56s , +08d 32m 50.9s) | P| | 470 | 17.0 | Coadd 854 | 2021-08-13 01:07:22 | MASTER-Tavrida | (00h 56m 48.35s , +08d 14m 14.6s) | P\ | 150 | 16.1 | 902 | 2021-08-13 01:08:05 | MASTER-IAC | (00h 59m 12.29s , +07d 57m 47.5s) | P| | 160 | 18.9 | 902 | 2021-08-13 01:08:05 | MASTER-IAC | (00h 58m 24.62s , +08d 02m 44.7s) | P- | 160 | 18.7 | 911 | 2021-08-13 01:08:15 | MASTER-Kislovodsk | (01h 00m 00.08s , +08d 07m 52.1s) | P- | 160 | 16.3 | 912 | 2021-08-13 01:08:15 | MASTER-Kislovodsk | (00h 59m 55.61s , +08d 31m 49.0s) | P| | 160 | 16.5 | 1038 | 2021-08-13 01:10:11 | MASTER-Tavrida | (00h 56m 40.82s , +08d 13m 07.9s) | P\ | 180 | 16.3 | 1092 | 2021-08-13 01:11:05 | MASTER-IAC | (00h 59m 18.07s , +07d 58m 13.7s) | P| | 180 | 18.9 | 1092 | 2021-08-13 01:11:05 | MASTER-IAC | (00h 58m 30.24s , +08d 03m 10.7s) | P- | 180 | 18.6 | 1102 | 2021-08-13 01:11:15 | MASTER-Kislovodsk | (01h 00m 01.28s , +08d 08m 52.3s) | P- | 180 | 15.6 | 1102 | 2021-08-13 01:11:15 | MASTER-Kislovodsk | (00h 59m 56.65s , +08d 32m 48.7s) | P| | 180 | 15.9 | 1237 | 2021-08-13 01:13:30 | MASTER-Tavrida | (00h 56m 47.22s , +08d 13m 07.5s) | P\ | 180 | 16.3 | 1292 | 2021-08-13 01:14:25 | MASTER-IAC | (00h 59m 16.05s , +07d 59m 28.3s) | P| | 180 | 18.9 | 1472 | 2021-08-13 01:14:25 | MASTER-IAC | (00h 59m 16.05s , +07d 59m 28.3s) | P| | 540 | 19.8 | Coadd 1292 | 2021-08-13 01:14:25 | MASTER-IAC | (00h 58m 28.03s , +08d 04m 25.3s) | P- | 180 | 18.7 | 1472 | 2021-08-13 01:14:25 | MASTER-IAC | (00h 58m 28.03s , +08d 04m 25.3s) | P- | 540 | 19.5 | Coadd 1436 | 2021-08-13 01:16:49 | MASTER-Tavrida | (00h 56m 43.91s , +08d 14m 33.0s) | P\ | 180 | 16.5 | 1492 | 2021-08-13 01:17:45 | MASTER-IAC | (00h 59m 16.03s , +07d 58m 00.8s) | P| | 180 | 18.9 | 1492 | 2021-08-13 01:17:45 | MASTER-IAC | (00h 58m 27.99s , +08d 02m 57.4s) | P- | 180 | 18.7 | 1692 | 2021-08-13 01:21:05 | MASTER-IAC | (00h 59m 19.72s , +07d 59m 27.8s) | P| | 180 | 18.9 | 1692 | 2021-08-13 01:21:05 | MASTER-IAC | (00h 58m 31.68s , +08d 04m 24.4s) | P- | 180 | 18.7 | 1832 | 2021-08-13 01:24:25 | MASTER-IAC | (01h 02m 54.77s , +07d 58m 50.4s) | C | 60 | 18.6 | 1832 | 2021-08-13 01:24:25 | MASTER-IAC | (00h 54m 47.04s , +08d 04m 10.4s) | C | 60 | 18.5 | 2073 | 2021-08-13 01:28:26 | MASTER-IAC | (01h 04m 28.98s , +08d 39m 17.4s) | C | 60 | 18.6 | 2073 | 2021-08-13 01:28:26 | MASTER-IAC | (00h 56m 20.95s , +08d 44m 37.3s) | C | 60 | 18.5 | 2159 | 2021-08-13 01:29:53 | MASTER-IAC | (01h 04m 18.57s , +06d 45m 19.4s) | C | 60 | 18.8 | 2159 | 2021-08-13 01:29:53 | MASTER-IAC | (00h 56m 12.85s , +06d 50m 38.5s) | C | 60 | 18.6 | 2239 | 2021-08-13 01:31:12 | MASTER-IAC | (01h 04m 54.89s , +10d 34m 56.1s) | C | 60 | 18.9 | 2239 | 2021-08-13 01:31:12 | MASTER-IAC | (00h 56m 44.12s , +10d 40m 16.4s) | C | 60 | 18.6 | 2319 | 2021-08-13 01:32:32 | MASTER-IAC | (00h 55m 57.65s , +04d 56m 56.9s) | C | 60 | 18.6 | 2399 | 2021-08-13 01:33:52 | MASTER-IAC | (01h 11m 51.00s , +08d 46m 45.3s) | C | 60 | 18.5 | 2479 | 2021-08-13 01:35:12 | MASTER-IAC | (01h 11m 25.54s , +06d 51m 45.4s) | C | 60 | 18.6 | 3165 | 2021-08-13 01:46:38 | MASTER-IAC | (01h 04m 35.83s , +08d 41m 07.8s) | C | 60 | 18.9 | 3165 | 2021-08-13 01:46:38 | MASTER-IAC | (00h 56m 28.07s , +08d 46m 27.5s) | C | 60 | 18.6 | 3245 | 2021-08-13 01:47:58 | MASTER-IAC | (01h 04m 12.26s , +06d 46m 13.0s) | C | 60 | 18.8 | 3245 | 2021-08-13 01:47:58 | MASTER-IAC | (00h 56m 06.81s , +06d 51m 31.9s) | C | 60 | 18.6 | 3326 | 2021-08-13 01:49:19 | MASTER-IAC | (01h 04m 51.02s , +10d 35m 16.0s) | C | 60 | 18.8 | 3326 | 2021-08-13 01:49:19 | MASTER-IAC | (00h 56m 40.51s , +10d 40m 36.5s) | C | 60 | 18.7 | 3406 | 2021-08-13 01:50:39 | MASTER-IAC | (00h 56m 00.81s , +04d 57m 29.8s) | C | 60 | 18.6 | 3486 | 2021-08-13 01:51:59 | MASTER-IAC | (01h 11m 44.33s , +08d 44m 44.5s) | C | 60 | 18.5 | 3566 | 2021-08-13 01:53:19 | MASTER-IAC | (01h 11m 30.53s , +06d 51m 06.1s) | C | 60 | 18.7 | 4211 | 2021-08-13 02:04:04 | MASTER-IAC | (01h 04m 28.84s , +08d 41m 11.7s) | C | 60 | 18.9 | 4211 | 2021-08-13 02:04:04 | MASTER-IAC | (00h 56m 20.65s , +08d 46m 31.4s) | C | 60 | 18.7 | 4291 | 2021-08-13 02:05:24 | MASTER-IAC | (01h 04m 17.37s , +06d 46m 10.2s) | C | 60 | 18.7 | 4291 | 2021-08-13 02:05:24 | MASTER-IAC | (00h 56m 11.51s , +06d 51m 29.7s) | C | 60 | 18.6 | 4371 | 2021-08-13 02:06:44 | MASTER-IAC | (01h 04m 51.49s , +10d 33m 12.8s) | C | 60 | 18.9 | 4371 | 2021-08-13 02:06:44 | MASTER-IAC | (00h 56m 40.56s , +10d 38m 33.5s) | C | 60 | 18.8 | 4455 | 2021-08-13 02:08:09 | MASTER-IAC | (00h 55m 58.70s , +04d 56m 38.8s) | C | 60 | 18.6 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.