TITLE: GCN CIRCULAR NUMBER: 19252 SUBJECT: GRB 160401A: MASTER-IAC prompt optical observations DATE: 16/04/01 22:07:26 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs R. Rebolo, M. Serra Ricart, N. Lodieu, G. Israelian The Instituto de Astrofisica de Canarias V. Lipunov, E.Gorbovskoy, V.Kornilov, D.Kuvshinov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov Lomonosov Moscow State University, Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Senik Kislovodsk Solar Station of the Pulkovo Observatory K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University V.Yurkov, Yu.Sergienko, A.Gabovich Blagoveschensk Educational State University, Blagoveschensk D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA) MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Teyde observatory was pointed to the GRB160401.85 (Mereghetti et al., GCN 19251) 7 sec after notice time and 15 sec after trigger time at 2016-04-01 20:20:57 UT. On our first (10s exposure) set we didn't find new optical transient within INTEGRAL error-box (ra=05 59 00 dec=+26 41 11 r=0.054) brighter then 16.3 (5-sigma upper limit). The message may be cited.