GCN Circular 18635
Subject
GRB 151027A: Maidanak optical observations
Event
Date
2015-11-22T21:48:09Z (10 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
A. Pozanenko (IKI), E. Mazaeva (IKI), A. Volnova (IKI), O. Burhonov
(UBAI) report on behalf of larger GRB follow-up collaboration:
We observed the Swift GRB 151027A (Maselli et al., GCN 18478) with
AZT-22 telescope of Maidanak observatory equipped with SNUCAM in R
filter. We obtained several images in R-filter on Oct., 30, Nov., 6 and
Nov., 9 under mean FWHM of about 0.9". The afterglow (Maselli et al.,
GCN 18478; Zheng and Filippenko, GCN 18479) is clearly detected in each
epoch. The afterglow is well separated from nearby source (Dichiara et
al.GCN 18510; Mazaeva et al., GCN 18559).
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2015-11-06 15:04:07 10.474 R 10*300 23.30 0.24
2015-11-09 14:06:04 13.443 R 10*300 23.33 0.20
The photometry is based on nearby USNO-B1.0 stars
USNO-B.1_id R2
1513-0237223 16.66
1513-0237251 16.81
1513-0237270 16.78
A preliminary light curve of the afterglow can be found in
http://grb.rssi.ru/GRB151027A/GRB151027A_lc.png
At this time it is unclear what is a reason of flattening of the light
curve at 11-13 days. It might be SN signature or it is continuing bumps
of the light curve previously seen at least on ~ 1.3 days and ~3 days.