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GCN Circular 2747

GRB040924: Afterglow magnitude at t=17.5hr
2004-09-25T14:10:40Z (20 years ago)
Johan U. Fynbo at U.Copenhagen <>
J. P. U. Fynbo (U. Copenhagen), A. Hornstrup (DSRI), J. Hjorth (U.
Copenhagen), B. L. Jensen (U. Copenhagen), Michael I. Andersen (AIP)
report on behalf or a larger collaboration:

"We have observed the afterglow of GRB 040924 (Fenimore et al. GCN
#2735; Fox et al. GCN #2734, GCN #2741) with the 2.56-m Nordic Optical
Telescope on La Palma. By stacking 9 300sec exposures in the R-band with
a mean epoch of Sep 25 5.25 UT we detect a source at the position of the
candidate afterglow reported by Fox et al. Assuming a magnitude of
R=19.1 for the nearby star U1050_00580520 we estimate that the afterglow
flux is around R=22.1 17.5 hours after the burst. This implies the the
lightcurve has become steeper than the slope of -0.7 during the first
hour reported by Fox et al. (GCN #2741)."    

[GCN OPS NOTE:  This circular was delayed 1.6 hr due to a change in the submiter's
email domain.]
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