Accurate early positions for<i>Swift</i>GRBs: enhancing X-ray positions with UVOT astrometry
Accurate early positions for<i>Swift</i>GRBs: enhancing X-ray positions with UVOT astrometry
The Swift Gamma Ray Burst satellite routinely provides prompt positions for GRBs and their afterglows on timescales of a few hundred seconds. However, with a pointing accuracy of only a few arcminutes, and a systematic uncertainty on the star-tracker solutions to the World Coordinate System of 3–4 arcsec, the precision …