[vsnet-grb-info 2219] GRB051001: Swift UVOT Upper Limits

[GCN Circulars]

TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  4058
SUBJECT: GRB051001: Swift UVOT Upper Limits 
DATE:    05/10/02 18:56:50 GMT
FROM:    Caryl Gronwall at PSU/Swift-UVOT  <caryl at astro.psu.edu>

F. Marshall(GSFC), A. Moretti (OAB), J. Nousek (PSU), W. Voges (MPE),
N. Gehrels (GSFC) report on behalf of the Swift/UVOT team.

The Swift/UVOT instrument began observing the field of the burst GRB051001
at 11:14:45 UT, 189 seconds after the BAT trigger (Moretti et al., GCN 4051).

Within the 6 arcsec radius XRT error circle (GCN 4051), no new optical/UV
source is detected. We derive the following 3-sigma upper limit magnitudes
on any optical/UV counterpart in the summed images in each UVOT filter
(from 6" radius apertures centered on the XRT location, which is
representative of the local background).

     Filter    T_range(sec)  Exp(sec)  3-sig UL

       V           189-289       100     18.9
       V         189-11522      1189     20.1
       B          335-6646      1077     21.2
       U          321-5738      1106     21.0
       UVW1      307-13221       952     20.9
       UVW2    11530-12429       900     21.4
       UVM2      6655-7435       780     21.5