[vsnet-grb-info 4154] GRB 061222b, SMARTS optical/IR afterglow observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  5961
SUBJECT: GRB 061222b, SMARTS optical/IR afterglow observations
DATE:    06/12/22 05:31:57 GMT
FROM:    Bethany Cobb at Yale U  <cobb at astro.yale.edu>

B. E. Cobb (Yale), part of the larger SMARTS consortium, reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 061222b
(GCN 5957, Racusin et al.), with a mid-exposure time of
2006-12-22 04:42:11 UT, which is ~0.5 hours post-burst.
Several dithered images were obtained in each filter,
with total summed exposure times of 180s in each of BRIYJK and
120s in each of H and V.

In the I-band a dim object is detected with a preliminary 
magnitude of I=20.7+/-0.4 at the position of the afterglow 
reported by Berger (GCN 5956).  This source is not significantly
detected in the J-band to a limiting magnitude of J<18.
Photometry is calibrated with USNO-B1.0 stars in the optical
and 2MASS stars in the IR.  Photometry is effect by high background 
due to the nearby bright star.