TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4381
SUBJECT: Possible GRB 051221B: MDM Optical Detection
DATE:    05/12/22 03:35:54 GMT
FROM:    Jules Halpern at Columbia U.  <jules@astro.columbia.edu>

J. P. Halpern & S. Tyagi (Columbia U.) report:

"We observed the position of possible Swift GRB 051221B
in the R-band with the MDM 1.3m for 30 minutes starting
on Dec. 22 01:31 UT, or 5.5 hours after the BAT trigger
(Boyd et al., GCN 4376).

We find an object of R=21.8 located at

RA(J2000) = 20h 49m 34.8s
Dec(J2000) = +53d 02' 11.8"

which is consistent in position with the fading XRT source
(Page et al., GCN 4378).  (We use a USNO B1.0 comparison star
at 20h 49m 36.08s, +53d 01' 29.65".)

We have not established any optical variability at this time."