TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1920 SUBJECT: GRB030227: Kiso optical upper limit DATE: 03/03/04 09:26:51 GMT FROM: Yuji Urata at RIKEN Y. Urata, T. Aoki on behalf of the Kiso GRB team and H. Izumiura (OAO) report: We re-examine our multi-band data obtained at Kiso observatory starting at 2.1 hour after the burst (Izumiura et al. GCN1900). We could not detect the optical afterglow ( S1-A ; Castro-Tirado et al. GCN 1904, Soderberg et al. GCN 1907, Berger et al. GCN 1910, Gorosabel et al. GCN 1915) down to limiting magnitudes estimated by comparison with the result of field photometry by Henden (GCN1917). Our data: Date Time (UT) Band Exposure Limiting mag.(SN=3) 02-27 10:43-11:03 R 300s x 3 21.1 11:05-11:24 I 300s x 3 20.1 11:27-11:32 V 300s x 3 20.9 11:49-12:08 B 300s x 3 21.7 12:44-12:54 R 600s 20.6 This message may be cited.