GCN Circular 22269
Subject
GRB 171222A: NOT Optical Afterglow
Date
2017-12-23T01:06:51Z (6 years ago)
From
Daniel Perley at Liverpool JMU <d.a.perley@ljmu.ac.uk>
D. A. Perley (LJMU), D. Malesani (DARK/NBI), K. Heintz (Univ. Iceland,
DARK/NBI), A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), and J. J. Lehiten
(MPS) report on behalf of a larger collaboration:
We obtained observations of GRB 171222A (Racusin et al., GCN 22265)
using StanCam on the Nordic Optical Telescope, beginning at 00:08:31 UT
on 2017-12-23. Imaging was obtained in both R and I bands.
In the raw images we identify an optical source, not visible in
pre-imaging from Pan-STARRS, at the following location within the XRT
error circle (Osborne et al. GCN 22266):
RA = 09:53:06.73
Dec = +35:37:35.5
We suggest that this source is the optical afterglow of GRB 171222A.
Provisional photometry relative to nearby USNO stars gives a magnitude
of R = 21.44 +/- 0.09 (at 7.67 hours after the GRB trigger).