TITLE:   GCN CIRCULAR
NUMBER:  2195
SUBJECT: GRB 030429: IR photometry with IRSF/SIRIUS
DATE:    03/05/02 12:25:44 GMT
FROM:    Nial Tanvir at IofA U.Cambridge  <nrt@ast.cam.ac.uk>

S. Nishiyama, D. Baba, T. Nagata (Nagoya U.), N. Matsunaga (U. of Tokyo),
and IRSF/SIRIUS team (Nagoya U., NAOJ), N. Kawai (Tokyo Tech), N. Tanvir
(U. of Hertfordshire) report:

We observed the SXC error box of GRB 030429 (HETE alert 2695) with the
Simultaneous three-color InfraRed Imager for Unbiased Survey (SIRIUS) on
the Nagoya-SAAO 1.4m telescope (IRSF).  For the afterglow candidate
proposed by Gilmore et al. (GCN 2184), we get the J H Ks magnitudes at 4
epochs begining 6.6 hrs after the burst:

   UTmid     J     H     Ks
Apr 29.727  18.8  17.8  17.0
Apr 29.873  19.2  18.3  17.5
Apr 30.005  18.9  18.1  17.4
----------------------------
Apr 30.768  19.0  18.4  17.8

We estimate the uncertainty in the magnitudes is about 0.2 mag. The Ks
magnitude seems to be consistent with that at April 30.20 reported by
Fynbo et al. (GCN 2185).  These observations confirm the fading
behaviour, but they were made under non-photometric conditions, and
the effect of the nearby NW source (GCN 2185) makes the photometry
less reliable, suggesting the results should be treated with caution.

This message may be cited.