[vsnet-grb-info 6473] GRB 080810: KANATA optical-NIR observation, update

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8085
SUBJECT: GRB 080810: KANATA optical-NIR observation, update
DATE:    08/08/10 19:35:44 GMT
FROM:    Makoto Uemura at Hiroshima U  <uemuram at hiroshima-u.ac.jp>

M. Uemura, M. Yamanaka, Y. Ikejiri, K. Sakimoto, T. Ohsugi, 
K.S. Kawabata, and A. Arai, report on behalf of the KANATA GRB team:

  We continue the observation of GRB 080810 with the KANATA 1.5-m 
telescope.  We obtained V, J, and Ks-band images of the field 
of the afterglow using TRISPEC.
The latest observation shows:

time(UT)    mag.   err   exposure time
Aug. 2008  
10.78444   18.92V  0.05   123sec * 10
10.78479   17.53J  0.31    72sec * 10

The light curve we obtained can be described with a simple 
power-law decay between 420 and 20000 sec after the GRB trigger, 
without an apparent break.  
The power-law index is calculated to be 1.21+/-0.02. 
The index is slightly, but significantly larger than that reported 
in GCN 8084, implying a possible break around the very early 
or very late phase of our observation period.  

Further monitoring is encouraged.