TITLE:   GCN CIRCULAR
NUMBER:  8308
SUBJECT: GRB 081001: Swift UVOT Observations
DATE:    08/10/02 17:29:21 GMT
FROM:    Erik Hoversten at Swift/Penn State  <hoversten@astro.psu.edu>

E. A. Hoversten (PSU), and H.A. Krimm (CRESST/GSFC/USRA) report on
behalf of the Swift UVOT team:

The Swift/UVOT began observations of the field of GRB 081001 14.5 ks
after the SuperAGILE dectection (Lazzarotto et al., GCN
Circ. 8305). No afterglow is detected within the Swift XRT error
circle (Page et al., GCN 8307) in any of the observed UVOT filters.

UVOT magnitude 3-sigma upper limits are reported in the following
table:

Filter   T_start   T_stop   Exp(s)  Mag (3-sigma upper limit)
-------------------------------------------------------------
v         16285    22214      350       > 19.84
b         15213    21209      416       > 20.90
u         14997    20992      416       > 20.51
uvw1      14568    20776      834       > 20.84
uvm2      16502    16696      191       > 19.81
uvw2      15431    22064     1670       > 21.65

The quoted upper limits have not been corrected for the large expected
Galactic extinction along the line of sight of E(B-V) = 2.63 mag
(Schlegel et al., 1998).  All photometry is on the UVOT photometry system
described in Poole et al. (2008, MNRAS, 383, 627).