[vsnet-grb-info 4174] GRB 061222A: MITSuME Akeno optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5979
SUBJECT: GRB 061222A: MITSuME Akeno optical upper limits
DATE:    06/12/24 23:19:43 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 (TokyoTech)
report on behalf of the MITSuME collaboration:
 
We observed the error box of GRB061222A (Grupe et al., GCN 5954)
with the 3-color 50cm MITSuME Telescope at Akeno, Japan starting 
at 8:48:53 UT, 5.3 hours after the trigger.   
In the co-added images of Ic, Rc, and g' bands, we did not detect
any new source in the XRT error circle.  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        8:48:53    09:32:23     60s * 36         19.6 
Rc        8:48:53    09:32:23     60s *	36	   20.4 
g'        8:48:53    09:32:23     60s * 36	   20.6
-----------------------------------------------------------------