TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  2761
SUBJECT: XRF 020903:  Observations of the Host Galaxy
DATE:    04/10/04 16:16:04 GMT
FROM:    Sabrina Savage at U of Wyoming  <sander@uwyo.edu>

We observed XRF 020903 with the CTIO 0.9-inch 32, 35, and 37 days
after the burst
and with the USNO 1.0-meter 32 and 60 days after the burst. We find no
evidence
for a rebrightening at these times.  Zero points for the g' and r'
filters used 
for the CTIO 0.9-meter images were taken from Smith, J. A. et al.,
2003, AJ,126, 2037 
(Table 3).  UBVRI standard star magnitudes were taken from Henden, A.
2002, GCN 1571.  

Due to poor seeing at USNO and the close proximity of the galaxy
complexes, a subtraction routine was performed with limited success on
the galaxies labeled G2 + G3 in Soderberg, A. M. et al., 2004, ApJ,
606, 994 (Figure 1) to determine the magnitude of the OT.  Within the
errors, the magnitude of the OT does not change between one and two
months post-burst and is thus taken as the magnitude of the G1 complex
(Soderberg et al. 2004).  

The CTIO images yield average magnitudes of  g' = 21.30 +/- 0.07 mag
and 
r' = 20.18 +/- 0.14 mag.  The USNO images yield average magnitudes of
R ~ 21 mag
and I ~ 20.4 mag.  These results are very consistent with prior
authors regarding the 
underlying host galaxy; however, the subtraction routine may be a
source of systematic error.

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