[vsnet-grb-info 21705] Swift Trigger 886157: MASTER optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23804
SUBJECT: Swift Trigger 886157: MASTER optical observation
DATE:    19/01/29 10:19:25 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

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

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

D. Buckley (South African Astronomical Observatory),

V. Yurkov, A. Gabovich, Yu. Sergienko, D. Kobcev (Blagoveschensk Educational State University, Blagoveschensk),

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

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

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

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


MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L)
located in South  African Astronomical Observatory,
was pointed to Swift Trigger 886157  (S. D. Barthelmy et al., GCN 23800; Barthelmy et al. ATel 12436; Ttrig=2019-01-28 01:22:25 UT) 
23 sec after notice time (370 sec after trigger time) at 2019-01-28 01:28:35 UT.

There is no new OT, connected with GRB, with mlim=19.4 (5-sigma upper 
limit) on first 70s-exposition image inside Swift BAT error-box.

There is no OT inside Swift XRT position (Kennea et al. ATel 12445)
on first MASTER images  (started at 2019-01-28 01:28:35) with mlim=19.4 
and
at 2019-01-29 01:44:03UT on 2 MASTER-SAAO inspect images with unfiltered mlim=20.0 (5-sigma).

The galactic latitude b = -2 deg., longitude l = 352 deg.
Alert observations started at zenit distance = 72 deg.
The moon (48 % bright part) was 41 deg. above the horizon. The distance between  moon and  object is 47 deg.
The sun  altitude was -25.6 deg.

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