GCN Circular 18581
Subject
GRB 151111A: LCOGT-FTS afterglow observations
Date
2015-11-11T17:05:15Z (8 years ago)
From
Simone Dichiara at Ferrara U/Italy <dichiara@fe.infn.it>
S. Dichiara (U. Ferrara, ICRANet), C. Guidorzi (U. Ferrara),
S. Kobayashi (LJMU), A. Gomboc (U. Ljubljana) on behalf of a
larger collaboration report:
The 2-m LCOGT Faulkes Telescope South began observing Swift
GRB 151111A (McCauley et al. GCN 18578) on November 11, 10:45 UT
(2.2 hours after the burst trigger) with SDSS R and I filters
under poor sky conditions. We do not detect any optical afterglow
candidate within the enhanced Swift-XRT error circle
(Goad et al. GCN 18579) with the following magnitudes:
Mid Time Exposure Filter Magnitude
(hours) (s)
-------------------------------------------------------
3.5 10x120 R > 20.5
4.2 9x120 I > 20.0
-------------------------------------------------------
Calibration is done against nearby USNOB-1 stars using R2 and I
nominal magnitudes.
We note in both filters the presence of a possible source of
R~21 mag at the following position: RA(J2000)=03:47:22.75,
DEC(J2000)=-44:09:43.6 (error radius of 1.5"). We caution that
the detection is not significant, so we cannot rule out the
possibility that it is a fluke.