TITLE: GCN CIRCULAR NUMBER: 21994 SUBJECT: GRB 171011A: MASTER-SAAO optical observations DATE: 17/10/11 19:12:29 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, D.Kuvshinov, A.V.Krylov, I.Gorbunov, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D. Vlasenko Lomonosov Moscow State University, Sternberg Astronomical Institut of MSU D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres 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 O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk, Irkutsk State University V.Yurkov, Yu.Sergienko Blagoveschensk Educational State University, Blagoveschensk A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in SAAO was pointed to the GRB171011A 34 sec after notice time and 273 sec after trigger time at 2017-10-11 18:37:20 UT. On our first (50s exposure) set we not found optical transient within SWIFT error-box (ra=236.758 dec=-10.0703 r=0.1) brighter then 17.7. The observations made on zenit distance = 80 degrees, galaxy latitude b = 33 degree. The moon (59 % bright part) below the horizon (The altitude of the Moon is -51 degree ). The sun altitude is -23.4 degree. The error box can be observed till sunrise at 2017-10-12 03:59:47. This message can be cited.