Аннотация: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.