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GCN Circular 261

GRB990123: Caltech STIS Photometry and Images
1999-02-19T13:52:30Z (25 years ago)
Steve Odewahn at Caltech <>
S. C. Odewahn, J. S. Bloom, S. Djorgovski, S. R. Kulkarni,
and F. Harrison (CIT) report on behalf of the Caltech-NRAO-CARA 
GRB Collaboration:

We have processed the HST STIS images of GRB 990123 using a variety
of techniques and have deduced the following magnitudes: 

Estimates of Gunn r magnitudes from the Median stack STIS image:
  r(OT)          = 25.25 -+0.2      systematic+accidental error
  r(OT+GAL)      = 24.16 -+0.1      accidental error only
  r(A2)          = 27.18 -+0.02     accidental error only
  r(OT+GAL+A2)   = 24.09          

Estimates of Gunn r magnitudes from the drizzled STIS image: 
  r(OT)          = 25.28 -+0.2    systematic+accidental error 
  r(OT+GAL)      = 24.12 -+0.1    systematic+accidental error 
  r(A2)          = 27.23 -+0.02   systematic+accidental error         
  r(OT+GAL+A2)   = 24.06         

Details of the reduction, the image properties and a map defining 
the apertures for OT, GAL, and A2 (a discrete source 0.9" from
the OT) may be found at:

In this website we detail the procedure for obtaining by anonymous 
ftp our final STIS images, a deep Keck R-band image, and the Palomar 
60-inch OT discovery image discussed in GCN 201.  These data may be 
used without any need to cite the source.

This message may be cited.
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