TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  165
SUBJECT: GRB981220 Optical Observations
DATE:    98/12/23 20:31:13 GMT
FROM:    Brad Schaefer at Yale  <schaefer@grb2.physics.yale.edu>

Bradley E. Schaefer (Yale) reports:

"I have obtained 19 images in the V and R bands of the joint RXTE/IPN
region for GRB981220.  The total integration time is 2.5 hours in the
V-band and 2.25 hours in the R-band, with the filters alternating in time,
for a total time span of just over 5 hours. These images were obtained
from 23 December 1998 00:52 to 05:55 UT with the Yale 1m telescope on
Cerro Tololo.

No variable source was identified in or near the GRB981220 region.
Comparisons were made with the Digital Sky Survey, for which no 'new'
stars appear.  Also, comparisons were made between the first and last
images, separated by roughly 5 hours of time.  For the latter comparison,
the limiting magnitude for detecting change is close to V=22.0 mag.  As
always, further analysis can push somewhat deeper, yet it is clear that
any associated optical transient must be close to this quoted limit if not
fainter."