GCN Circular 2063

Subject: GRB 030329: KAIT optical photometry

Weidong Li, Ryan Chornock, Saurabh Jha, and Alexei V. Filippenko (UC Berkeley)
report:

We have observed the GRB 030329 afterglow (Peterson & Price, GCN 1985
Loading...
 
 ) with 
the Katzman Automatic Imaging Telescope (KAIT) on the nights of 2003 Mar 30 
and 31 UT. 16 sets of UBVRI images were taken. Aperture photometry was
performed on the afterglow and some local standard stars in IRAF, and the 
instrumental magnitudes were transformed to the standard BVRI system using
the calibration provided by Henden (GCN 2023
Loading...
 
 ). We have also applied color
corrections to the KAIT data based on well-measured color terms for the KAIT
filters. Due to the lack of U-band calibrations, only BVRI images were reduced.
Our R-band photometry is summarized in the table below.  The errors quoted
include both the IRAF aperture photometry error and the magnitude
transformation error.


Table: KAIT R-band observations

t-t0 (hours) exptime   mag   err

 16.5662  300.0  R  15.424  0.034
 17.0989  150.0  R  15.448  0.032
 17.4775  150.0  R  15.487  0.022
 18.4173  150.0  R  15.618  0.028
 18.7934  150.0  R  15.659  0.023
 19.6814  300.0  R  15.724  0.023
 20.1812  150.0  R  15.809  0.057
 20.6912  150.0  R  15.825  0.016
 21.0689  150.0  R  15.899  0.030
 21.4514  150.0  R  15.907  0.035
 21.8964  150.0  R  15.948  0.035
 22.2831  150.0  R  15.965  0.037
 22.6695  150.0  R  16.102  0.079
 43.1320  300.0  R  16.560  0.031
 44.6242  300.0  R  16.763  0.136   (observed under cloudy conditions)
 45.9700  300.0  R  16.600  0.135   (observed under cloudy conditions)

This message may be cited.