TITLE: GCN CIRCULAR NUMBER: 29504 SUBJECT: IceCube Alert 210213.78: Global MASTER-Net observations report DATE: 21/02/13 19:13:07 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-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 IceCube Alert 210213.78 (trigger No 1103075,10h 21m 01.92s , -35d 23m 56.4s, R=1.19) errorbox 111 sec after notice time and 149 sec after trigger time at 2021-02-13 18:42:53 UT, with upper limit up to 19.3 mag. Observations started at twilight. The observations began at zenith distance = 58 deg. The sun altitude is -15.1 deg. The galactic latitude b = 18 deg., longitude l = 272 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1546655 We obtain a following upper limits. Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment _________|_____________________|_____________________|____________________________________|_____|_______|_______|________ 164 | 2021-02-13 18:42:53 | MASTER-SAAO | (10h 21m 38.22s , -35d 24m 19.9s) | C | 30 | 18.7 | 218 | 2021-02-13 18:43:42 | MASTER-SAAO | (10h 21m 35.40s , -35d 22m 52.5s) | C | 40 | 18.8 | 283 | 2021-02-13 18:44:42 | MASTER-SAAO | (10h 21m 35.44s , -35d 24m 25.4s) | C | 50 | 18.9 | 358 | 2021-02-13 18:45:52 | MASTER-SAAO | (10h 21m 37.95s , -35d 22m 57.7s) | C | 60 | 19.1 | 447 | 2021-02-13 18:47:11 | MASTER-SAAO | (10h 21m 32.52s , -35d 23m 37.2s) | C | 80 | 19.2 | 556 | 2021-02-13 18:48:50 | MASTER-SAAO | (10h 21m 33.21s , -35d 22m 37.0s) | C | 100 | 19.2 | 686 | 2021-02-13 18:50:50 | MASTER-SAAO | (10h 21m 37.47s , -35d 23m 37.9s) | C | 120 | 19.1 | 841 | 2021-02-13 18:53:10 | MASTER-SAAO | (10h 21m 32.34s , -35d 24m 39.1s) | C | 150 | 18.9 | 1025 | 2021-02-13 18:55:59 | MASTER-SAAO | (10h 21m 38.27s , -35d 24m 21.5s) | C | 180 | 19.3 | 1225 | 2021-02-13 18:59:19 | MASTER-SAAO | (10h 21m 34.81s , -35d 22m 51.4s) | C | 180 | 19.2 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.