GCN Circular 2686
Subject
GRB040825A: Optical observations
Date
2004-09-01T11:30:49Z (20 years ago)
From
Brian Lindgren Jensen at U.of Copenhagen <brian_j@astro.ku.dk>
Brian L. Jensen (U. Copenhagen), Arnaud Cassan (IAP, Paris), Dijana
Dominis (U. Potsdam), Jens Hjorth, Johan Fynbo (U. Copenhagen), Michael
I. Andersen (AIP, Potsdam), Javier Gorosabel (IAA-CSIC, Granada) report:
"We report optical observations, covering ~90% of the refined 7'
error-circle (HETE#11553-2) of GRB040825A, taken with the Danish 1.54m
telescope at La Silla (FoV=13.7'), as follows:
Date midobs (UT) | t_b+ | filter:expt | seeing | 3sig limit
------------------------------------------------------------
Aug. 26.30, 2004 27.7h R:14x600s ~1.1" R~23.5
Aug. 26.31, 2004 27.9h V:12x600s ~1.4" V~23.3
Aug. 27.31, 2004 51.9h R:18x600s ~1.5" R~23.0
Aug. 28.28, 2004 75.2h I:13x300s ~2.1" I~21.0
Photometric calibration is based on Henden et al. (GCN#2668).
Visual comparison of the three main epochs reveals no candidate optical
afterglow down to R~23.0"
[GCN OPS NOTE (02Sep04 11:15 UT): The second column (t_b+) of the table
had a wrong offset in the original posting (should have been 12.8h larger).
This archived copy of the circular has the corrected t_b+ values.]