TITLE: GCN CIRCULAR NUMBER: 14316 SUBJECT: Swift XRT observations of GRB 130310A DATE: 13/03/15 22:03:36 GMT FROM: Boris Sbarufatti at INAF-OAB/IASFPA B. Sbarufatti (INAF-OAB/PSU), D. N. Burrows (PSU), P. E. Evans (U Leicester) report on behalf of the Swift XRT team: Swift performed a total of 7 pointings for this burst on March 11th: 4x1ks covering the Fermi LAT error circle (Guiriec et al., GCN #1482) and 3x1.5 ks covering the IPN error box (Golenetskii et al., GCN #14284). We detect a total of 5 sources: # RA DEC Err counts rate(counts/ks) 1 09 28 45.9 -17 18 49.5 7.4" 9 11 (+11/-7) 2 09 29 27.0 -17 30 13.8 6.8" 12 13 (+14/-8) 3 09 28 59.0 -17 00 40.8 5.4" 8 9 (+10/-7) 4 09 27 58.9 -17 12 57.9 8.6" 10 11 (+12/-7) 5 09 27 31.7 -17 08 55.3 11.0" 5 4.7 (+6/-4) The fluxes are computed at the 99% confidence level, following Kraft, Burrows & Nousek (1991). The background level was computed both generally, using the 'background' task of XIMAGE on each pointing, and locally, using the 'sosta' task of XIMAGE, and selecting the highest value. All sources are inside the LAT error circle, but only source #5 is inside the IPN error box. Swift performed another observation in the direction of source #5 on March 13th, with a 3.4 ks exposure. The 99% confidence level upper limit at the position of source #5 is 4.6E-3 counts/s, which does not give strong evidence for fading. No further observations are planned. This circular is an official product of the Swift-XRT team.