TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3039
SUBJECT: GRB050219a: No Swift UVOT Detection of Afterglow Emission
DATE:    05/02/19 22:46:56 GMT
FROM:    Pete Roming at PSU  <roming@astro.psu.edu>

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

The Swift Ultra-Violet/Optical Telescope (UVOT) began observations of 
GRB050219a on February 19, 2005, at 12:41:21 UT, 80 seconds after the 
initial Swift BAT trigger (Hullinger et al, GCN 3038).  We detect no source 
at the Swift XRT position (Romano et al, GCN 3036).  The limiting 
magnitudes in each of the UVOT filters are as follows:

  UVW2 ~ 21.0 (3-sigma) for a combined 277 second exposure starting @ 80 
seconds after the burst
  UVM2 ~ 20.8 (3-sigma) for a combined 277 second exposure starting @ 201 
seconds after the burst
  UVW1 ~ 21.7 (3-sigma) for a combined 287 second exposure starting @ 216 
seconds after the burst
  U ~ 21.6 (3-sigma) for a combined 280 second exposure starting @ 230 
seconds after the burst
  B ~ 21.5 (3-sigma) for a combined 278 second exposure starting @ 245 
seconds after the burst
  V ~ 20.7 (3-sigma) for a combined 374 second exposure starting @ 96 
seconds after the burst

We caution that the instrument is not yet fully calibrated and that the 
magnitude limits presented here may need to be refined.