TITLE: GCN CIRCULAR NUMBER: 23330 SUBJECT: GRB 181011A: Global MASTER Net optical inspection DATE: 18/10/12 15:33:40 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory K. Ivanov, O. Gres, N.M. Budnev, S. Yazev, O. Chuvalaev, V. Poleshchuk Irkutsk State University V. Yurkov, A. Gabovich, Yu. Sergienko Blagoveschensk Educational State University, Blagoveschensk R. Podesta, Carlos Lopez and F. Podesta Observatorio Astronomico Felix Aguilar (OAFA) Hugo Levato and Carlos Saffe 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, S. Potter, A. Kniazev, M. Kotze South African Astronomical Observatory 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 starting survey on the IPN GRB181011.15 error-box (K. Hurley et al GCN 23328) 33218 sec after notice time and 61888 sec after trigger time at 2018-10-11 20:47:47 UT. The 5-sigma upper limit on our images is about 19 mag. MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station) was starting survey on the IPN GRB181011.15 error-box 45716 sec after notice time and 74386 sec after trigger time at 2018-10-12 00:16:05 UT. The 5-sigma upper limit on our images is about 19 mag. MASTER-Net cover full IPN (K. Hurley et al. GCN 23328) and MAXI (Kawakubo et al. GCN 23327) error boxes. Coverage map is available here: http://master.sai.msu.ru/static//IPN/db/GRB181011.15/img/ligo_master_2018-10-12-05-03-00.eb.zoom.1.pngmlimit.png