GCN Circular 105

S. Odewahn, C. Thomas, S. Djorgovski and S. Kulkarni report that
the  optical counterpart to GRB980613 detected by BeppoSAX was
searched for with the Palomar 60" on Jun15,98 and Jun16,98 (UT).
Images were obtained with CCD13 in Gunn gri at an airmass of 1.6
and integration times of (900,600,600) seconds respectively under
photometric conditions and seeing measured at 1.0" fwhm. Images and
details of observations are given in:

  http://astro.caltech.edu/~sco/sco1/research/grb/grb980613.html

  The faintest source shown in our map at r=20.96 (object 6 in Fig1) is
detected at better than 5-sigma.  No such source (r<21) has been found
to vary in the MECS error box with delta mag greater than 0.5 mags in
the period from Jun15,98 to Jun1698 (UT).  In Figure 2 of our web page
we show the Jun15 and Jun16 (UT) 600 second r images from the Palomar 60"
with the latest position and errorbox from the L. Piro (MECS).  The 8'
diameter error box is centered on 10:17:45.6 +71:29:56.0 (J2000). The
Jun16 image is shifted into the coordinate system of the Jun15 image. We
also show for comparison the corresponding DSS field. A more thorough
photometric analysis of the our images will be reported following the
completion of our Palomar observing run (Jun18,98).



[GCN Operator's Note:  This circular was received at 10:44 UT, but due to
a computer network problem at GSFC its distribution was delayed until now.
GSFC and GCN apologize for the delay.]