GCN Circular 11261

M. H. Siegel (PSU), S. D. Barthelmy (GSFC), M. M. Chester (PSU),
P. A. Evans (U Leicester), J. M. Gelbord (PSU), J. A. Kennea (PSU),
K. L. Page (U Leicester) and R. L. C. Starling (U Leicester) report on
behalf of the Swift Team:

Swift began a target of opportunity observation of GRB 100909A
on September  9, 2010 at 12:18 UT, approximately 3.2 hours
after the burst was detected by INTEGRAL. Swift data for these
observations utilize Target ID 20147. 

The XRT began observing the field at 12:19:37.4 UT, 11.7 ks after the
INTEGRAL trigger. In 1.8 ks of promptly downlinked data there is a faint source,
detected at the 3.2-sigma level at: RA, Dec= 73.94797, +54.65798 which is 
equivalent to:

RA (J2000) : 04h 55m 47.51s
Dec (J2000): +54d 39' 28.7''

with an estimated uncertainty of 6 arcsec (radius, 90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White
filter  starting 11687 seconds after the INTEGRAL trigger. No credible
afterglow  candidate has been found in the initial data products. The
2.7'x2.7' sub-image  covers 44% of the INTEGRAL error circle and 100%
of the XRT error circle. The typical 3-sigma upper limit has  been
about 19.6 mag. The coverage of the INTEGRAL and XRT error circles by
the 8'x8'  region for the list of sources generated on-board is
uncertain because the  large number of sources filled the available
telemetry. No correction has been  made for the expected extinction
corresponding to E(B-V) of 0.51. 

Burst Advocate for this burst is M. H. Siegel (siegel AT astro.psu.edu). 
Please contact the BA by email if you require additional information
regarding Swift followup of this burst. In extremely urgent cases, after
trying the Burst Advocate, you can contact the Swift PI by phone (see
Swift TOO web site for information: http://www.swift.psu.edu/too.html.)