TITLE: GCN CIRCULAR NUMBER: 31048 SUBJECT: GRB 211105A: MASTER optical inspection DATE: 21/11/06 09:54:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru> V. Lipunov, E.Gorbovskoy, K.Zhirkov, N.Tiurina, P.Balanutsa, A.Kuznetsov, O.Gress,G.Antipov, D. Vlasenko, V.Senik,V.Topolev, A.Chasovnikov, E.Minkina, V.Grinshpun, D.Cheryasov (Lomonosov MSU,SAI,PhysicsDepartment), R. Rebolo, M. Serra(The Instituto de Astrofisica de Canarias), D. Buckley (South African Astronomical Observatory), N.M. Budnev (Irkutsk State University, API), C.Francile, R. Podesta, F. Podesta (OAFA), A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory), A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity) MASTER Global robotic net (MASTER-Net:http://observ.pereplet.ru Lipunov et al.,2010,Advances in Astronomy,2010,30L) started inspect of GECAM GRB 211105A (Zhao et al. GCN 31046, R.A.Dec(2000)=81.93,-57.38 +-1.27d; Ttrigger=2021-11-05T 04:35:20.200 UT, Tnotice=2021-11-06 01:59:33UT) by MASTER-OAFA (Argentina) at 2021-11-06 07:10:26UT (1 day 9306s after trigger time) with upper limit up to 19.7 mag. The observations began at zenith distance = 26 deg. The sun altitude is -27.4 deg. The galactic latitude b = -34 deg., longitude l = 266 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1777102 We obtained the following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment 95796 | 2021-11-06 07:10:26 | MASTER-OAFA | (05h 24m 16.75s , -56d 44m 09.4s) | C | 180 | 18.5 | 95996 | 2021-11-06 07:13:46 | MASTER-OAFA | (05h 24m 22.29s , -56d 44m 03.5s) | C | 180 | 18.8 | 96176 | 2021-11-06 07:13:46 | MASTER-OAFA | (05h 24m 22.29s , -56d 44m 03.5s) | C | 540 | 19.7 | Coadd 96196 | 2021-11-06 07:17:05 | MASTER-OAFA | (05h 24m 18.69s , -56d 42m 43.7s) | C | 180 | 18.8 | 96395 | 2021-11-06 07:20:25 | MASTER-OAFA | (05h 24m 18.52s , -56d 44m 01.5s) | C | 180 | 18.8 | 96595 | 2021-11-06 07:23:44 | MASTER-OAFA | (05h 24m 21.21s , -56d 42m 41.0s) | C | 180 | 18.9 | 96775 | 2021-11-06 07:23:44 | MASTER-OAFA | (05h 24m 21.21s , -56d 42m 41.0s) | C | 540 | 19.7 | Coadd 96794 | 2021-11-06 07:27:04 | MASTER-OAFA | (05h 24m 15.79s , -56d 43m 26.0s) | C | 180 | 18.9 | 96993 | 2021-11-06 07:30:23 | MASTER-OAFA | (05h 24m 14.75s , -56d 42m 26.5s) | C | 180 | 18.9 | 97193 | 2021-11-06 07:33:43 | MASTER-OAFA | (05h 24m 21.18s , -56d 43m 26.8s) | C | 180 | 19.0 | Filter C is a clear (unfiltred) band. The observation and reduction will be continued The message may be cited.