GCN Circular 19623

V. Sokolov, A. Valeev, A. Moskvitin and V. Komarova (SAO RAS)
report on behalf of a larger team.

We observed the error box of INTEGRAL GRB 160629A (Gotz et al.
GCNC #19621) with the SAO RAS 6-meter telescope BTA + Scorpio.
The observations started since ~10 minutes after the trigger.
Several images in Rc band were obtained.

We find a fading source with the coordinates

R.A. =  00:19:27.1
Dec. = +76:58:00.7
error = 0".5

This object is consistent with the OT reported by Klotz et al.
(GCNC #19622).

We used USNO-B1 star 1669-0002297 (R.A = 00:19:31.12;
Dec. = +76:57:41.3) with R2 = 15.53 for the calibrations.
Preliminary magnitudes of OT are as following.

T-T0,s  exp,s  R_mag  err
==========================
 615     30    17.40  0.03
 688     60    17.55  0.03
 848    180    17.71  0.02
1039     60    17.85  0.05
1118     30    18.13  0.08
1393     80    18.21  0.09
1508     80    18.24  0.11
1648     80    18.41  0.10
1964    180    18.55  0.09
3859    180    19.25  0.07
4066    180    19.18  0.04
4262    180    19.25  0.04
4483    180    19.29  0.11
4725    180    19.24  0.05
4926    180    19.24  0.03
5132    180    19.33  0.04
5347    180    19.30  0.04
5585    180    19.43  0.05
5824    180    19.44  0.06

ftp://ftp.sao.ru/pub/grb/GRB160629A/GRB160629A_BTA.jpg