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GCN Circular 2741

Subject
GRB040924: Optical afterglow properties
Date
2004-09-25T05:31:19Z (20 years ago)
From
Derek Fox at CIT <derekfox@astro.caltech.edu>
D.B. Fox (Caltech) reports on behalf of a larger collaboration:

"Further analysis of our Robotic P60 observations of the candidate
optical afterglow of GRB040924 (GCNs 2734, 2735) reveals that the
candidate afterglow fades by 0.87 +/- 0.08 mag from our first exposure
(mean epoch 12:07:57 UT) to our last exposure (mean epoch 12:42:09
UT).  Referenced to the time of the burst this corresponds to a decay
with power-law index alpha approximately equal to -0.7.

The coordinates of the candidate referenced to the GSC-2.2 are:

    RA 02:06:22.55, Dec +16:06:48.8 (J2000)

with coordinate uncertainties of approximately 0.2".  

Photometric calibration of the data against the F-emulsion magnitudes
of the GSC-2.2 yields an R-band magnitude of the candidate at our
first epoch (945 sec after the burst) of R=18.0 mag.

Images and a finding chart for the candidate may be found at:
 <http://www.astro.caltech.edu/~derekfox/grb040924/>."
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