TITLE: GCN CIRCULAR NUMBER: 22481 SUBJECT: GRB 180314A: MASTER-Net OT dtetction DATE: 18/03/14 08:04:37 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E.Gorbovskoy, N.Tyurina, V.Kornilov, D.Zimnukhov, V.Vladimirov, A.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.Chazov, D. Kuvshinov (Lomonosov Moscow State University, SAI), R. Rebolo, M. Serra-Ricart (The Instituto de Astrofisica de Canarias), R.Podesta, C.Lopez, F. Podesta (Observatorio Astronomico Felix Aguilar (OAFA),National University of San Juan, Argentina), H. Levato, C. Saffe (Instituto de Ciencias Astronomicas,de la Tierra y del Espacio (ICATE), San Juan, Argentina), D.Buckley, S. Potter (South African Astronomical Observatory), O.Gres, N.M.Budnev (Irkutsk State University), A. Tlatov, V.Senik, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory) V.Yurkov, A.Gabovich, Yu.Sergienko (Blagoveschensk Educational State University, Blagoveschensk), MASTER-IAC and MASTER-OAFA automatically pointed to GRB 180314A (D'Avanzo et al. GCN 22478, Osborne et al. GCN 22480) with optical transient detection by MASTER auto-detection system. We confirm Swift and GROND OT (D'Avanzo et al. GCN 22478, Bolmer et al. GCN 22479). There are also synchronous images from MASTER very wide field cameras (MASTER-VWFC). MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru ,Lipunov et al. Advances in Astronomy, 2010, 30L) located in Teyde observatory(Spain) was pointed to the GRB180314.03 7 sec after notice time and 100 sec after trigger time at 2018-03-14 00:45:11 UT. On our first (20s exposure) set we found 1 optical transient within SWIFT error-box (ra=99.275 dec=-24.4908 r=0.05) : T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 110 2018-03-14 00:45:11 20 ( 6h 37m 03.7s , -24d 29m 45.8s) 15.36 The 5-sigma upper limit on the first 20s image is 17.2mag The observations made on zenit distance = 83 degrees, galaxy latitude b = -13 degree. The moon (12 % bright part) below the horizon (The altitude of the Moon is -59 degree ). The sun altitude is -63.5 degree. MASTER-OAFA robotic telescope located in Argentina was pointed to the GRB180314A 17 sec after notice time and 110 sec after trigger time at 2018-03-14 00:45:21 UT. On our first (20s exposure) set we found 1 optical transient within SWIFT error-box (ra=99.275 dec=-24.4908 r=0.05) T-Tmid Date Time Expt. Ra Dec Mag ---------|---------------------|-------|-----------------|-----------------|------- 120 2018-03-14 00:45:21 20 ( 6h 37m 03.7s , -24d 29m 45.8s) 15.60 The 5-sigma upper limit on first 20s image is 18.4 mag The observations made on zenit distance = 15 degrees, galaxy latitude b = -13 degree. The moon (12 % bright part) below the horizon (The altitude of the Moon is -37 degree ). The sun altitude is -23.5 degree. The message may be cited.