[vsnet-grb-info 4254] GRB 070125: MITSuME Okayama optical observation

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  6050
SUBJECT: GRB 070125: MITSuME Okayama optical observation
DATE:    07/01/29 03:34:14 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida at oao.nao.ac.jp>

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

We detected the optical afterglow candidate of GRB 070125
reported by by Cenko and Fox (GCN 6028) with the 50cm MITSuME
Telescope at Okayama Astrophysical Observatory on January 26
UT. Photometric calibration was done using USNO-B1.0 catalog
magnitudes of eight stars around the target. The results are
following.

  UT 26 January 2007  12:25 - 17:23  mid-UT 14:53
    total exp time 123 min. (1 min. exp. x 123 frames)
    ------------------------------
     g'  19.6 mag. +/- 0.2 mag.
     Rc  18.8 mag. +/- 0.2 mag.
     Ic  18.0 mag. +/- 0.3 mag.
    ------------------------------

  Time variability in Rc
          UT        mid-UT  exp.time    Rc mag.
    -----------------------------------------------
    12:25 - 13:06   12:45   30 min.   18.9 +/- 0.3
    13:07 - 14:35   13:51   37 min.   19.0 +/- 0.3
    16:01 - 16:44   16:22   30 min.   18.7 +/- 0.2
    16:44 - 17:23   17:03   26 min.   19.4 +/- 0.4

-------------------------------------------------
              $B!!!!5HEDF;Mx(B
    $B9qN)E7J8Bf!!2,;3E7BNJ*M}4QB,=j!!=jD9(B
            Michitoshi Yoshida, Dr.
 Director of Okayama Astrophysical Observatory,
   National Astronomical Observatory of Japan
   Phone:+81-865-44-2155 FAX:+81-865-44-2360
            yoshida at oao.nao.ac.jp
-------------------------------------------------