GCN Circular 4861
Subject
GRB060306: APO Ks-band Imaging Observations
Date
2006-03-12T04:41:38Z (18 years ago)
From
Hsiao-Wen Chen at U Chicago <hchen@oddjob.uchicago.edu>
H.-W. Chen (U Chicago), X. Fan (U Arizona), F. Hearty (Colorado), M. Bayliss
(Chicago), D. Q. Lamb (U Chicago), R. McMillan (APO), B. Ketzeback (APO), J.
Barentine (APO), J. Dembicky (APO), and D. York (U Chicago) report:
"We obtained a 3x300 sec dithered exposures in Ks of the field of
GRB060306 (Angelini et al., GCN 4848), using the NIC-FPS near-infrared camera
on the 3.5 m telescope at the Apache Point Observatory. The
observations started at 20060306.10 UT (~ 2 hrs after the initial
Swift trigger) through variable clouds and under a mean seeing
condition of 1 arcsec. Calibrating the final stacked image to 2MASS
stars in the field gives a 5 sigma depth of Ks=20.4 over a 1 arcsec diameter
aperture. Within the XRT error circle (Page et al., GCN 4850), we locate a
single source at
RA(J2000) = 02:44:23.0
Dec(J2000) = -02:08:51.2,
which is also present in the DSS red plate (see also Price et al.,
GCN 4854, and Nysewander et al., GCN 4857). Based on the 2MASS photometry,
we estimate the source brightness to be Ks=18.3 +/- 0.1 mag. Comarison with
the Ks image taken a day later by Nysewander et al. (GCN4857) shows no
variability of this source.
The stacked image is available at
http://lambda.uchicago.edu/public/grb/grb060306/grb060306K.fits.
NIC-FPS is currently in its commissioning phase."