GCN Circular 18559
Subject
GRB 151027A: Mondy optical observations
Date
2015-11-04T17:58:29Z (9 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP),
A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the Swift GRB 151027A (Maselli et al., GCN 18478) with
AZT-33IK telescope of Sayan observatory (Mondy) on several epochs. We
obtained
images in R-filter on Oct., 27-- Nov., 1 . The afterglow (Maselli et al.,
GCN 18478; Zheng and Filippenko, GCN 18479) is clearly detected in each
epoch. Coordinates of the afterglow are (J2000) 18 09 56.66 +61 21 13.0 with
uncertainties of 0.3 arcsec in each coordinate. We also detected the
USNO-B1.0 source mentioned in GCN 18510 (Dichiara et al.) in a position
(J2000) 18 09 56.44 +61 21 10.8 with uncertainties of 0.3 arcsec in each
coordinate.
Preliminary photometry of the afterglow on October-29 -- November, 1 is
following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2015-10-29 13:18:41 2.4082 R 55*60 19.84 0.05
2015-10-30 12:11:18 3.3736 R 78*60 20.32 0.06
2015-10-31 12:47:18 4.3958 R 41*120 21.25 0.07
2015-11-01 12:28:18 5.3694 R 19*120 21.50 0.12
The photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id R2
1513-0237223 16.66
1513-0237170 15.58
1513-0237251 16.81
1513-0237270 16.78
Late time photometry could be influenced by the nearby USNO-B1.0 source.
The overall light curve of our observations as well as photometry reported
in GCNs 18480, 18521,18558 can be found in
http://grb.rssi.ru/GRB151027A/GRB151027A_lc.png
