[vsnet-grb-info 12883] GRB 130215A: Additional P200 NIR observations
GCN Circulars
gcncirc at capella2.gsfc.nasa.gov
Sun Feb 17 19:56:52 JST 2013
TITLE: GCN CIRCULAR
NUMBER: 14227
SUBJECT: GRB 130215A: Additional P200 NIR observations
DATE: 13/02/17 10:56:45 GMT
FROM: Daniel Perley at Caltech <dperley at astro.caltech.edu>
D. A. Perley (Caltech) reports:
I re-observed the location of GRB 130215A with the Wide-Field Infrared
Camera (WIRC) on the Palomar 200-inch telescope on 2013-02-17 UT between
02:09 and 02:37 and between 04:29 and 04:56. Images were again taken in
J, H, and Ks-bands; transmission and seeing conditions were good.
The NIR afterglow remains well-detected in the most recent images.
Photometry of the Ks-band images gives the following magnitudes (Vega):
t_mid=48.75 hours : Ks = 17.57 +/- 0.05 mag
t_mid=51.07 hours : Ks = 17.60 +/- 0.07 mag
Relative to the previous night (GCN 14222), these observations show
remarkably little fading (decay index alpha~0.4 between 25-50 hours,
compared to alpha~1.5 earlier; Butler et al., GCN 14212). This could
indicate contribution from a bright host galaxy, but no obvious
extension of the source is seen (in 1" seeing). Alternatively it could
indicate a bump, plateau or flare in the light curve. Further
observations with WIRC are not planned, but observations elsewhere are
encouraged to constrain further evolution of the afterglow.
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