TITLE:   GCN CIRCULAR
NUMBER:  23392
SUBJECT: GRB 181030A: MASTER Net OT detection
DATE:    18/10/30 06:57:40 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina,  P.Balanutsa, A.Kuznetsov, V.Vladimirov, D. Vlasenko
Lomonosov Moscow State University, SAI, Physics Department

A. Tlatov, V.Senik, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

D. Buckley,
South African Astronomical Observatory

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

O. Gres, N.M. Budnev, O.Ershova, Yu.Ishmuhametov
Applied Physics Institute, Irkutsk State University

V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk

R. Podesta, Carlos Lopez, F. Podesta, C.Francile
Observatorio Astronomico Felix Aguilar (OAFA)

H. Levato
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)


MASTER Global Robotic Net (http://observ.pereplet.ru , 
Lipunov et al. Advances in Astronomy, 2010, 30L http://adsabs.harvard.edu/abs/2010AdAst2010E..30L)
started Swift GRB 181030A (Sonbas et al. GCN23389, Beardmore et al. GCN23391)
optical alert observations 21 sec after notice time at  2018-10-30 01:29:03 UT

MASTER-Kislovodsk robotic telescope, located in Russia (Lomonosov MSU, Kislovodsk Solar Station of Pulkovo observatory)
  was pointed to the  GRB181030A 21 sec after notice time and 101 sec after trigger time at 2018-10-30 01:29:03 UT.
On our first 20s expos. set , started at 2018-10-30 01:29:03 UT,
we  found optical transient within SWIFT error-box
MASTER OT J094742.25+143925.73 (also detected by Sonbas et al SwiftUVOT GCN23389 and by Moskvitin et al. GCN 23390)
with m_OT=16.5 and falling light curve in both polarization filters.

The galactic latitude b = 46 deg., longitude l = 220 deg.
The observations made on zenit distance = 47 deg.
The moon (68 % bright part) was 67 deg. above the horizon.The distance between  moon and  object was 39 deg
The sun  altitude  was -24.2 deg.

MASTER-Tavrida robotic telescope located in Russia (Lomonosov MSU, SAI Crimea astronomical station)
was pointed to the  GRB181030A 31 sec after notice time and 105 sec after 
trigger time at 2018-10-30 01:29:13 UT.
The observations started on zenit distance = 51 deg.
The moon (68 % bright part) was 66 deg. above the horizon. The distance between  moon and  object was 39
The sun  altitude  was -27.9 deg.