TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2239
SUBJECT: GRB030324: Further Observations of the Candidate Optical Afterglow
DATE:    03/05/20 23:41:06 GMT
FROM:    Don Lamb at U.Chicago  <lamb@oddjob.uchicago.edu>

D. Q. Lamb, M. Nysewander, D. Reichart, D. G. York, R. McMillan, J.
Barentine, J. Dembicky, and B. Ketzeback report on behalf of the ARC
and UNC GRB teams of the FUN GRB collaboration:

Using a larger sample of standard stars from Henden (GCN 1950), we
measure the magnitude of the candidate optical afterglow (Lamb et al.
GCNs 2139, 2140) of GRB030324 (Donaghy et al., GCN 1954, 1955) on the
night of March 24 UT to be i* = 23.48 +/- 0.21 (S/N = 4.3).

On May 3 UT, we obtained a further five 600-second i* images of the
field of the candidate optical afterglow.  We find no object at the
location of the candidate optical afterglow down to the limiting
magnitude of the stacked image, which is i* = 25.1 (2 sigma).  We also
find no object at the location of the candidate optical afterglow down
to the limiting magnitude of the stacked image constructed by combining
the 1200-second i* image obtained on April 5 UT (Lamb et al. GCNs 2139,
2140) and the five 600-second i* images obtained on May 3 UT, which is
i* = 25.3 (2 sigma).

This further rules out the possibility that the star-like object we
detected on the night of March 24 UT is a variable star and places a
limit on the brightness of the host galaxy of GRB030324 of i* > 25.3
(2 sigma), if the object is the optical afterglow of GRB030324.