GCN Circular 5985

It has come to our attention that the SDSS photometry released for  
the burst GRB061126 was not calibrated with the correct photometric  
zero-points measured for the runs associated with these images.  We  
have found the problem in the scripts use to generate our GRB  
followup messages and it has been corrected so this will not affect  
any other future bursts. We have also verified that this problem does  
not affect any other data previously released for other bursts.     
The photometry previously released for GRB061126 should not be used  
for photometric calibration of new data.  This includes both the  
photometric zero-points in the catalogs we released for this burst as  
well as the photometric zero-points of the associated images.

We would like to emphasize that this error occurred due to a mistake  
in our GRB pre-burst scripts and is not due to a problem with the  
SDSS reductions themselves.

At the URL:

http://mizar.as.arizona.edu/grb/public/GRB061126/

We have replaced our previously released data with the official SDSS  
reduction of these data (which does not suffer from the same zero- 
point error).  This data is suitable for photometric calibration.    
At this time, we have only included an updated version of the bright  
star photometry and astrometry in the file  
GRB061126_sdss.calstar_v2.dat.  The format for this file is identical  
to that of previous releases.  We have also included images for this  
field from SDSS.  *These images have not been corrected for the  
incorrect photometric zero-points, so no photometric measurements  
should me made directly from the images*.

We regret this mistake and apologize for any confusion or  
inconvenience it may have caused.