TITLE: GCN CIRCULAR NUMBER: 23444 SUBJECT: GRB 181123B: Global MASTER Net optical inspection DATE: 18/11/24 15:49:54 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa,A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institute R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias D. Buckley, South African Astronomical Observatory A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory O. Gres, N.M. Budnev, Yu.Ishmuhametova Applied Physics Institute of Irkutsk State University V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk MASTER-OAFA robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the GRB181123B (Lien et al.,GCN 23432) at 2018-11-23 08:15:00 UT. On our 4-th (180s exposure) set we not found optical transient within Swift error-box (ra=184.367 dec=14.5975 r=0.05) brighter than 17.0. The galactic latitude b = -60 deg., longitude l = 98 deg. The observations made on zenit distance = 32 deg.The moon ( 1 % bright part) below the horizon (The altitude of the Moon is -44 deg. ). The sun altitude is -50.0 deg. The object can be observed till 2018-10-10 09:24:14 MASTER-Kislovodsk robotic telescope (MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory) was pointed to the GRB181123B (Lien et al., GCN 23432) 63194 sec after notice time and 63194 sec after trigger time at 2018-11-23 23:06:17 UT. On our 10-th (180s exposure) set , obtained 72767 sec after tigger time at 2018-11-24 01:45:51 UT, we not found optical transient within Swift error-box (ra=184.367 dec=14.5975 r=0.05) brighter than 18.1. The galactic latitude b = 75 deg., longitude l = 272 deg. The observations made on zenit distance = 53 deg.The moon (99 % bright part) is 34 deg. above the horizon. The distance between moon and object is 106 The sun altitude is -26.2 deg. The object can be observed till sunrise at 2018-11-24 04:14:26