[vsnet-grb-info 21756] Swift Trigger 887541: MASTER inspect

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23855
SUBJECT: Swift Trigger 887541: MASTER inspect
DATE:    19/02/04 08:31:54 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

V. Lipunov, E. Gorbovskoy, N.Tyurina, V.Kornilov, D.Vlasenko, V.Vladimirov, 
D.Zimnukhov, 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),

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

O. Gress, N.M. Budnev, O.Ershova, Yu.Ishmuhametova (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, v.2010, 30L),
located in South African Astronomical Observatory,
inspected Swift Trigger 887541  error-box (Barthelmy  et al. GCN23849, 21:18:17 UT; XRT_RA,Dec= 262.2442, -36.2421 +-4.7arcsec)
since  2019-02-04 00:16:44UT (Lipunov et al. GCN 23851).

There is no OT connected with GRB, inside Swift-XRT error-box with the
following unfiltered (W=0.2B+0.8R by USNO-B1 field stars, MASTER FOV=4sq.deg.)
upper limits (5sigma):

Tstart                Exp,s mlim 
2019-02-04 00:16:44   1800  20.0
2019-02-04 00:16:44    540  18.6
2019-02-04 00:16:44    180  17.5
2019-02-04 00:35:06    180  18.4
2019-02-04 00:38:43    180  18.4
2019-02-04 01:04:45    540  19.7
2019-02-04 01:15:31    540  19.9
2019-02-04 01:30:35   1800  20.0
2019-02-04 02:23:41    540  19.8 
2019-02-04 02:48:42    540  19.8

The observations started when error-box altitude was 9 deg.
The sun altitude was -38deg.
The message may be cited.