TITLE: GCN CIRCULAR NUMBER: 23070 SUBJECT: FRB 180725A: MASTER optical observations of the Fast Radio Burst error box DATE: 18/08/01 14:51:47 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, N.Tiurina, E. Gorbovskoy, V.Kornilov, A.Kuznetsov, V.Chazov, I. Gorbunov, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov, D. Vlasenko Lomonosov Moscow State University,SAI D. Buckley, South African Astronomical Observatory (SAAO) R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres The Instituto de Astrofisica de Canarias (IAC) A. Tlatov, V.Senik, D. Dormidontov Kislovodsk Solar Station of the Pulkovo Observatory R. Podesta, F. Podesta, C. Lopez, C.Francile Observatorio Astronomico Felix Aguilar (OAFA) H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE) O. Gres, N.M.Budnev , Yu.Ishmuhametova Irkutsk State University (ISU) A. Gabovich, V. Yurkov, Yu. Sergienko Blagoveschensk Educational State University (BSPU) In the process of regular survey, several MASTER telescopes accidentally shot the Fast Radio Burst error box near the date of the FRB 180725 So MASTER Global Robotic Net (http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) observed FRB 180725A error-box ( Boyle et al. ATel #11901 , Trigger-time 2018-07-25 17:59:43.115 UTC ) at: MASTER-Tavrida Date,UT unfiltered_mlim 2018-07-26 21:01:59-21:19:23 18.0 (Error-box_Altitude:23deg., SunAltitude:-25) Nearest in time images unfiltered_mlim 2018-05-20 20:37:00 18.9 MASTER-Kislovodsk : Date,UT unfiltered_mlim 2018-07-26 20:30:48-20:52:30 18.0 (Error-box_Altitude: 22deg. , SunAltitude:-26deg. ) 2018-07-27 21:19:48,21:28:51 18.5 (Error-box_Altitude: 24deg. SunAltitude:-27deg. ) Nearest in time UT images 2018-07-08 23:16:15 19.1 MASTER-Amur Date,UT unfiltered_mlim 2018-07-25 15:41:28 15.2 (Error-box_Altitude: 30deg., SunAltitude: -20deg.) MASTER-IAC nearest in time images: Date,UT unfiltered_mlim 2017-12-20 06:37:13 18.5 There is no OT detection yet. The covered map is vailable at http://master.sai.msu.ru/static/FRB180725A.jpg MASTER will reobserved this error-box in nearest night. The message may be cited.