GCN Circular 4471
Subject
GRB 060110: IR Candidate Afterglow
Date
2006-01-10T12:29:54Z (18 years ago)
From
Josh Bloom at UC Berkeley <jbloom@astron.berkeley.edu>
J. S. Bloom (UC Berkeley) reports:
"We have conducted further analysis on the source noted in GCNs
4465/4467 and suggest that, while the source is formally outside of
the 90% containment BAT error circle (e.g. Torii GCN 4468), there is
evidence this is the (bright) afterglow of GRB 060110 (Zane al. GCN
4463). This follows from a few lines of evidence:
[1] evidence for fading. We created two mosaic epochs (1: 08:06:52
-- 08:11:32; 2: 08:12:46 -- 08:30:36) and found that the average
brightness decreased by ~0.12 mag in JHKs. We believe that this
fading is significant but photometry is complicated by large
background gradients owing to the proximity to the Moon.
[2] no bright minor planets are nearby this position (see GCN 4467).
[3] no evidence for apparent motion between the epochs (~<1"/hr)
and point-like PSF.
All the other minor planets in the field have significant
motions, particularly in RA (>10"/hr)
Our current astrometric solution gives a position of the afterglow
(in both epochs) to be:
04:50:57.85 +28:25:55.7
(J2000; 200 mas uncertainty). This is close to the position noted by
Torii (GCN 4468) and lends credence to their tentative R-band
detection. Photometry in the second epoch yields magnitudes J =
15.23, H = 14.25, Ks = 13.57 (absolute zp uncertainty of ~0.04 mag)."
Follow on observations are urged.