GCN Circular 15809
Subject
GRB 140209A: P60 optical afterglow detection
Date
2014-02-09T09:29:44Z (10 years ago)
From
Daniel Perley at Caltech <dperley@astro.caltech.edu>
D. A. Perley (Caltech) reports on behalf of a larger collaboration:
The Palomar 60-inch telescope responded automatically to the Swift alert
for GRB 140209A (Cenko et al., GCN 15808) and began a sequence of
60-second exposures in r, i, and z filters at 07:35:30 UT, 4.55 minutes
after the BAT trigger. In the reduced images, we clearly detect a
fading, uncatalogued optical counterpart inside the BAT error circle at
the following location:
RA = 05:25:19.034
Dec = +32:29:53.18
(+/- 0.6 arcsec)
Calibrated relative to USNO-B1.0, the source fades steadily from R=17.6
in the first r-band image to R=19.4 at 41.1 minutes post-GRB, which
identifies it as the likely optical afterglow of this event.