[vsnet-grb-info 5645] GRB080212: Optical afterglow candidate observed by MITSuME Telescope

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  7305
SUBJECT: GRB080212: Optical afterglow candidate observed by MITSuME Telescope
DATE:    08/02/13 11:50:53 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida at oao.nao.ac.jp>

M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama (OAO, NAOJ)
and N. Kawai (Tokyo Tech) report on behalf of the MITSuME
collaboration:

We performed optical imaging observation (g', Rc, and Ic) of the
field of GRB 080212 (Ziaeepour et al. GCN 7296) with 50cm MITSuME
telescope at Okayama Astrophysical Observatory from UT 17:36:37
(124 sec after the trigger) to UT 20:30:38 on Feb 12 2008.

We found a 18 mag star in the vicinity of the XRT position (Goad
et al. GCN 7300). This is the late-K star reported by Berger (GCN
7304). Although we could not spatially resolve the faint source
close to this star reported by Berger (GCN7304), we found that
a fading component is overlaid on the star. This component is
a GRB afterglow candidate. We estimated the magnitudes of the
fading component by subtracting the flux of the star at 2 hours
after the trigger from the star magnitude at early time.

The estimated magnitudes of the fading component are summarized
below.

Observation date  2008-02-12 UT

mid-UT    exp-T         g'           Rc           Ic
---------------------------------------------------------
17:42:47   10min   19.46+-0.26  17.77+-0.15  17.98+-0.22
18:00:27   22min   > 21.0       18.77+-0.14  18.91+-0.21
18:19:08   52min   > 21.0       19.88+-0.10  > 20.5
18:58:37  113min   > 21.0       > 20.5       > 20.5
---------------------------------------------------------