TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3182
SUBJECT: GRB 050406: Early observations with Swift-UVOT
DATE:    05/04/06 19:07:04 GMT
FROM:    Martin Still at NASA/GSFC Swift SSC  <Martin.Still@gsfc.nasa.gov>

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

The Swift Ultra-Violet/Optical Telescope (UVOT) began settled 
observations of the field of GRB 050406 (Parsons et al; GCN 3180) at 
16:00:16 UT, 88s after the BAT trigger.  The first data taken after 
spacecraft settling was a 100s V image with pixel size 0.5x0.5 arcsec 
and a field of view of 17x17 arcmin. Mid-exposure time was 138s after 
the trigger. A comparison against the Digitized Sky Survey reveals no 
new sources in the field down to a 3-sigma background limit of V = 
18.8. This limit is based upon preliminary flight calibrations.