TITLE: GCN GRB OBSERVATION REPORT NUMBER: 818 SUBJECT: GRB000926 - Optical observations DATE: 00/09/29 22:11:05 GMT FROM: Christian Veillet at CFHT GRB000926 - Optical observations The optical counterpart of GRB000926 has been observed using the CFH12K CCD mosaic camera at the prime focus of the 3.6-m CFH Telescope. One 600s exposure with moderate seeing (image quality between 0.9" and 1.0") has been obtained and a preliminary reduction using the reference star of Halpern et al. (GCN #806) with R=17.1 gives the following measurement for GRB000926: Sept. 29.3075 R = 21.23 +/- 0.05 Added to the R-band data points used in the analysis by Hjorth et al. (GCN #814), this new point confirms a pure power law decay with a decay value of 1.69 +/- 0.03, which is not significantly different from Hjorth et al.'s determination. An image of the area around the GRB can be found at http://www.cfht.hawaii.edu/~veillet/grb.html Kocevski, Donovan and G. Luppino 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/ ************************************************************