TITLE: GCN CIRCULAR NUMBER: 14323 SUBJECT: GRB 130315A: Swift/UVOT Upper Limits DATE: 13/03/16 20:19:38 GMT FROM: Stephen Holland at STScI S. T. Holland (STScI) and P. A. Evans (U Leicester) report on behalf of the Swift/UVOT team: Swift/UVOT began settled observations of the field of GRB 130315A starting 171 s after the BAT trigger (Evans et al., 2013, GCNC 14311). We do not detect any new source within the XRT error circle (Page et al., 2013, GCNC 14317). Preliminary UVOT 3-sigma upper limits at this position are presented below. ------------------------------------------------ Filter TSTART TSTOP Exposure Mag ------------------------------------------------ white (FC) 171 321 147 >21.1 u (FC) 330 580 246 >20.3 ------------------------------------------------ v 4476 23,657 1136 >20.7 b 3860 28,925 1685 >21.7 u 330 17,889 1443 >21.4 uvw1 4887 17,764 1995 >21.3 uvm2 4681 16,857 1277 >21.0 uvw2 4271 22,898 1279 >21.2 white 171 29.424 1022 >22.2 ------------------------------------------------ The quoted upper limits have not been corrected for the Galactic extinction along the line of sight to this burst of E_{B-V} = 0.32 mag (Schlafly et al. 2011, ApJS, 737, 103). The photometry is in the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373). The photometry is affected by the presence of a J = 15.4 mag 2MASS source 10301128-5147395 located 2.3 arcsec south of the XRT position.