TITLE:   GCN CIRCULAR
NUMBER:  10370
SUBJECT: GRB 100205A: Swift UVOT upper limits
DATE:    10/02/05 17:37:38 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU) and J. L. Racusin (NASA/GSFC) report on behalf
of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 100205A
177s after the BAT trigger (Racusin et al., GCN 10361). We do not
detect any source at the enhanced Swift XRT position (Racusin et al.,
GCN 10361) nor at the position of the Gemini-North K-band detection
(Tanvir et al., GCN 10366).  UVOT magnitude 3-sigma upper limits are
reported in the following table:

Filter  T_start  T_stop  Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
white     177      327    147      > 20.76
white     177     1533    392      > 21.31
v         665     1580     94      > 18.84
b         763     1162     38      > 19.25
u         335     1311    265      > 20.08


The quoted upper limits have not been corrected for the expected
Galactic extinction along the line of sight of E_(B-V) = 0.02 mag
(Schlegel et al. 1998). All photometry is on the UVOT photometric
system described in Poole et al. (2008, MNRAS, 383, 627).