[vsnet-grb-info 21315] GRB 181110A: Kanata 1.5m optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23414
SUBJECT: GRB 181110A: Kanata 1.5m optical observation
DATE:    18/11/10 10:26:30 GMT
FROM:    Koji Kawabata at HASC,Hiroshima U  <kawabtkj at hiroshima-u.ac.jp>

M. Yamanaka, M. Kawabata, K. S. Kawabata (Hiroshima Univ.) 
report on behalf of Kanata team:

We performed optical imaging polarimetry to the field of the
GRB 181110A (Evans et al. GCN 23413) from 2018-11-10 08:44:48 UT 
(77 seconds after the trigger) with HOWPol attached to the 1.5-m 
Kanata telescope at Higashi-Hiroshima Observatory, Japan. Although
the first frames were severely affected by bright twilight sky, 
in later frames a possible bright optical counterpart of the GRB 
appeared at the position consistent with the Swift-UVOT observation
(Evans et al. GCN 23413). The magnitude of the counterpart was 
R~14 mag (USNO B1.0) at 940 seconds after the trigger, suggesting
it brightened by ~4 mag within ~15 minutes. It further brightened
slightly (by a few 0.1 mag) and then declined smoothly. 
Further analysis is ongoing.