TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3077
SUBJECT: GRB 050306: No Swift UVOT Optical Counterpart Detected
DATE:    05/03/08 12:41:47 GMT
FROM:    Pete Roming at PSU  <roming@astro.psu.edu>

A. Blustin (MSSL), P. Brown (PSU), S. Rosen, K. McGowan, M. De Pasquale 
(MSSL), P. Boyd (GSFC/UMBC), S. T. Holland, M. Still (GSFC/USRA), W. 
Landsman (GSFC), S. Hunsberger (PSU), A. Breeveld (MSSL), P. Roming (PSU), 
K. Mason, P. Schady (MSSL), M. Ivanushkina (PSU), T. Poole (MSSL), C. 
Gronwall (PSU), B. Hancock (MSSL), S. Koch (PSU), M. Carter, H. Huckle 
(MSSL),  P. Broos (PSU), T. Kennedy, P. Smith (MSSL), J. Nousek (PSU), N. 
Gehrels (GSFC), on behalf of the Swift UVOT team.

The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of 
GRB050128 (GCN 3071) on February 7, 2005 at 14:58:53 UT. Before this time 
GRB 050306 was within the Swift Moon avoidance angle.  Over an 8,630s 
exposure combined from four snapshots between 35 and 41 hours after the 
trigger, we detect no new or variable source down to a V magnitude of 21.2 
(5-sigma upper limit)  in the BAT error circle. This includes the position 
of the X-ray candidate reported in GCN 3072.