TITLE:   GCN CIRCULAR
NUMBER:  15541
SUBJECT: GRB 131128A: Kanata/HOWPol optical observation
DATE:    13/11/29 03:01:30 GMT
FROM:    Koji Kawabata at HASC,Hiroshima U  <kawabtkj@hiroshima-u.ac.jp>

K. S. Kawabata, R. Itoh, N. Ebisuda, I. Ueno (Hiroshima Univ.) 
report on behalf of Kanata team:

We performed a series of optical imaging (polarimetric mode) for 
the optical afterglow of GRB 131128A (Sonbas et al., GCN 15533; 
Xu et al., GCN 15535; Gorbovskoy et al, GCN 15536; Goad et al., 
GCN 15538; Sonbas et al., GCN 15540) using HOWPol attached to 
the 1.5-m Kanata telescope at Higashi-Hiroshima Observatory, Japan. 

Our first 30 sec exposure began at t=360 sec since Swift/BAT trigger
and we detected the afterglow located at 9" west and 4" north of the 
bright star, USNO-B 2766-00858-1 (R2 = 11.63 mag). The magnitude of 
the afterglow is preliminarily estimated to be about R=17.5, although 
it might be still contaminated by the neaby bright star. The afterglow
quickly decayed and became fainter than ~18 mag at t=620 sec.