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GCN Circular 1949

GRB030323, possible optical counterpart
2003-03-24T19:40:26Z (21 years ago)
Arne A. Henden at USNO/USRA <>
A. Gilmore and P. Kilmartin (U. Canterbury) and
A. Henden (USRA/USNO) report:

We have imaged the inner 20x20arcmin of the error circle for
the HETE burst GRB030323 (HETE trigger 2640)
with the Mt. John 0.6m telescope (unfiltered, using
Rc zeropoint) and the USNO 1.0m telescope (Rc filter).
Located in the northern part of the error circle,
we find one fading object that may be the
optical counterpart to GRB030323.  This object does
not appear on any of the ESO/AAO red plates.  Its position,
along with two preliminary comparison stars (photometry
from Henden, GCN 1948), is:

Star       R.A. (2000)  Dec.      Rc
  A     11 06 15.21  -21 47 19.4  14.91
  B     11 06 08.36  -21 45 42.5  16.94
OT     11 06 09.38  -21 46 13.3

where coordinates are based on USNO-A2.0.  A 4x4arcmin
R-band finding chart can be found at
Photometry of the candidate with respect to these two stars yields:

   UTmid(hr) mag   Filter
   07.5868  18.69   Rc
   10.4750  19.56   CR
   12.2083  19.72   CR
   13.6555  19.96   CR
   14.7333  20.42   CR

Photometric errors range from 0.06mag at the beginning to
0.4mag towards the end.

These observations were made as part of the AAVSO GRB
Network, and supported by a grant from the Curry Foundation.

[GCN OPS NOTE (25mar03): The acknowledgement sentence at the end
was added as per author's request.]
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