TITLE:   GCN CIRCULAR
NUMBER:  4147
SUBJECT: GRB 051021: PROMPT RcIc Observations
DATE:    05/10/23 06:53:44 GMT
FROM:    Melissa Nysewander at UNC,Chapel Hill  <mnysewan@physics.unc.edu>

M. Nysewander, C. Macleod, D. Reichart, A. Crain, A. Foster report on
behalf of the UNC team of the FUN GRB Collaboration:

Under the control of Skynet, PROMPT observed the localization of GRB 051021
(Yoshida et al., GCN 4116; Fox et al., GCN 4120) beginning 12.9 hours after
the burst, in Rc and Ic simultaneously.

We do not detect the afterglow of the burst.  In two 90 x 60 sec
integrations of mean epoch 14.2 hours after the burst, we measure 3-sigma
limiting magnitudes of Rc = 20.7 and Ic = 20.4 based on 5 USNO-B1.0 stars.

PROMPT is still being built and commissioned.