[vsnet-grb-info 4170] GRB 061222B: MITSuME Akeno optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5977
SUBJECT: GRB 061222B: MITSuME Akeno optical upper limits
DATE:    06/12/24 15:32:47 GMT
FROM:    Nobuyuki Kawai at Tokyo Tech  <nkawai at hp.phys.titech.ac.jp>

T. Ishimura, Y. Yatsu, T. Shimokawabe, N. Vasquez, and N. Kawai (Tokyo
Tech) report on behalf of the MITSuME collaboration:

We observed the error box of GRB061222B (Racusin et al., GCN 5957)
with the 3-color 50cm MITSuME Telescope at Akeno, Japan starting at
12:52:28 UT, 8.7 hours after the trigger.   
In the co-added images of Ic, Rc, and g' bands, we did not detect
the afterglow (Berger, GCN 5956).  The 3-sigma limiting
magnitudes based on USNO-B1.0 (I-band) and NOMAD (R-band,g'-band)
stars are following.

Filter   start time   end time    Exp(s)    Mag (3-sigma upper limit)
-----------------------------------------------------------------
Ic       12:52:28    13:29:50     60s * 29       18.3
Rc       12:52:28    13:29:50     60s * 29	 19.7
g'       12:52:28    13:29:50     60s * 29	 19.4
-----------------------------------------------------------------