[vsnet-grb-info 16789] Swift 650221/IGR J00291+5934: Liverpool Telescope observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  18070
SUBJECT: Swift 650221/IGR J00291+5934: Liverpool Telescope observations
DATE:    15/07/26 06:55:38 GMT
FROM:    Drejc Kopac at Math Phys U,Slovenia  <drejc.kopac at fmf.uni-lj.si>

D. Kopac (U Ljubljana), C. Guidorzi (U Ferrara), C.G. Mundell (U Bath), 
I.A. Steele (LJMU), A. Gomboc (U Ljubljana), on behalf of a large 
collaboration report:

The 2-m Liverpool Telescope automatically began observing Swift Trigger 
650221/IGR J00291+5934 (Barthelmy et al., GCN 18061) with RINGO3 
polarimeter, starting 5 minutes post BAT trigger. Observations continued 
for 2 hours. At the position consistent with Fox & Kulkarni 2004 (ATel 
#354), and D'Avanzo et al. 2007 (A&A, 472, 881), we clearly detect the 
optical counterpart. The estimated magnitude is R = 18.07 +- 0.03 at 
36.4 minutes post trigger, calibrated against nearby USNO-B1.0 stars.