GCN Circular 1344
N. Kawai, Y. Urata (Titech/RIKEN), M. Kohama, K. Torii (RIKEN), A. Yoshida (AGU/RIKEN), K. Ayani, T. Kawabata (Bisei Astronomical Observatory), M. Chaya, H. Shibata, K. Sakamoto, M. Yamauchi (Miyazaki Univ.) on behalf of the RIBOTS/RIMOTS team We have observed covering the entire error circle of GRB020331 (Ricker et al. GCN 1315) field with the RIMOTS 30-cm telescope. The observations started at an early epoch (+1.6 hours after the burst). All the images were taken with 15 sec exposure and stacked for deeper inspection. From a comparison with the DSS-2 images we did not identify any new point source for the GRB. We summarize the observing time and the R-band limiting magnitude (SN=3), which was estimated by the comparison of our non-filter data with the R band field photometry by Henden (GCN 1319). Summary of observations on 2002/03/31 Time(UT) Limiting R mag start end (SN=3) 18:10 18:59 14.9 15s x 39 frames combined 19:00 19:59 14.2 15s x 51 frames combined 20:00 20:12 13.7 15s x 13 frames combined This message may be cited.