GCN Circular 2761

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
Loading...
 
 .  

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.

This message can be cited.