GCN Circular 253
Subject
GRB19990123 observations
Date
1999-02-08T17:31:10Z (25 years ago)
From
Christian Veillet at CFHT <veillet@cfht.hawaii.edu>
Christian Veillet reports:
The optical transient (OT) associated with the gamma ray burst
GRB990123 has been observed with the new wide field camera CFH12k
at the prime focus of the 3.6-m CFH Telescope for three consecutive
nights on 1999 Feb 5.6, 6.6 and 7.6 by C. Veillet in the course
of the French GRB follow-up program at CFHT (M. Boer, CESR, C. Veillet, CFHT).
A composite image of the field around the OT has been made
from eighteen 10min exposures (six per night). Using the standards
published by Nilakshi et al. (GCN 252), the mean R magnitude
of the OT averages to R = 23.45 (0.1) on 1999 Feb 6.6.
Images of the field, with a detection limit of R=25.0 (3 sigma),
can be seen at the Web site http://www.cfht.hawaii.edu/~veillet/grb990123.html.
No object is detected in a radius of 5" centered on the OT.
This message may be cited.