GCN Circular 6079
Subject
GRB 070208: Early IR detection and afterglow astrometry
Date
2007-02-08T11:00:33Z (18 years ago)
From
Josh Bloom at UC Berkeley <jbloom@astron.berkeley.edu>
J. S. Bloom (UC Berkeley) reports on behalf of a large group:
We began observing GRB 070208 (Sato et al. GCN 6074) with the robotic
IR telescope PAIRITEL at 2007-02-08 09:12:26 UTC, 1 minute 52 seconds
after the trigger. Consistent with the position of the fading source
reported by Guidorzi et al. (GCN 6077; see also Fox et al. 6078) we
find a new IR point source, offset from the nearby SDSS galaxy.
Astrometry of the afterglow position relative to 2MASS gives a
location of (J2000):
RA: 13:11:32.607
DEC: +61:57:54.37
(rms uncertainty of 350 mas in both coordinates). Adopting the
nominal SDSS position for the center of the putative host (Mirabal et
al. 6075), the afterglow is offset by 2.48" W, 2.77" S.
In a stacked exposure from 2007-02-08 09:12:26 to 09:28:44 we find a
preliminary magnitude of J=17.52 +/- 0.16, Ks=16.19+/-0.18.
A finder showing the XRT position (Sato et al. 6074; yellow circle),
SDSS sources (white squares), and the FTN optical afterglow position
may be found at:
http://lyra.berkeley.edu/~jbloom/grb070208.ps.gz
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