TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1003 SUBJECT: GRB010222 - Optical observation DATE: 01/03/03 00:39:04 GMT FROM: Christian Veillet at CFHT The optical counterpart of GRB010222 has been observed using the CFHT Multi Object Spectrograph in imaging mode at the Cassegrain focus of the 3.6-m CFH Telescope on the night of March 1 to 2. Two 10 mn images were obtained with a seeing of about 0.8". Photometric reduction made as outlined on GCN #1000 leads to: Mar. 2.641 R = 23.10 +/- 0.10 The index of the power law decay fitting the R light curve data since 0.6 days after the burst (including the revised and new measurements by Holland et al. in GCN #1002) is 1.25 +/- 0.03, the same as our previous determination (Veillet, GCN #1000) and not significantly different from the GCN #1002 value. While a few objects are now seen in a radius of 4", the OT is still a point like object. More information (with the new images of the OT) can be found at http://www.cfht.hawaii.edu/~veillet/grb.html M. Pakull, L. Mirioni, and J. McDonald are acknowledged for their help in this observation. This message may be cited. -- ************************************************************ Dr. Christian Veillet, CFHT Senior Resident Astronomer Phone: (808) 885-3161 http://www.cfht.hawaii.edu/~veillet/ ************************************************************