GCN Circular 23847
Subject
GRB 190203A: SAO RAS optical observations, afterglow fading
Date
2019-02-03T18:43:44Z (5 years ago)
From
Moskvitin Alexander at SAO RAS <mosk@sao.ru>
A. S. Moskvitin and O. I. Spiridonova (SAO RAS),
A. A. Volnova (IKI RAS), report on behalf of larger collaboration.
We observed the field of the GRB 190203A (Lien et al. GCNC #23845)
with the Zeiss-1000 telescope of SAO RAS (+ CCD photometer),
started on February, 3, 15:54:38 UT (10.5 min after the trigger).
We clearly detected the OT in the first few 300 sec. Rc band frames
(coordinates are consistent with the reported UVOT position).
Preliminary measurements of the OT brightness are as following:
T_start, UT T_end T_mid-T0, h exp., s R +/- R_err
15:54:38 16:11:51 0.318 3 x 300 19.34 +/- 0.08
16:12:54 16:30:11 0.624 3 x 300 20.46 +/- 0.12
16:30:54 17:19:23 1.183 8 x 300 21.23 +/- 0.14
OT is fading quickly with the slope about -1.3.
The photometry is based on the nearby USNO-B1 stars.
No correction has been made for the Galactic extinction.