TITLE: GCN GRB OBSERVATION REPORT NUMBER: 623 SUBJECT: GRB000301C - R magnitude lower limit DATE: 00/04/05 01:33:30 GMT FROM: Christian Veillet at CFHT The candidate for the optical transient (OT) associated with the gamma ray burst GRB000301C has been observed using the CFH12K CCD mosaic camera at the prime focus of the 3.6-m CFH Telescope in the course of the French GRB follow-up program at CFHT (M. Boer, CESR, C. Veillet, CFHT). Three 12 mn exposures with moderate seeing (image quality around 0.9") have been coadded. There is nothing visible at the location of the OT. The nearby galaxy (thought to be the host for some time before the HST observations) has a magnitude of R= 24.5 +-0.1, confirming the previous determinations (GCN592 - GCN598). The faintest objects detected in the neighborhood are at around R=26. We can infer the following lower limit: R > 26.0 on 2000 April 4.6 It is compatible with the alpha = -2.7 power law decay given in GCN611, and not with alpha = -2.1 given earlier, which would lead to R~25.6 at the same epoch. Further imaging is planned if the seeing gets better. Jean-Charles Cuillandre is acknowledged for his 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/ ************************************************************