TITLE: GCN CIRCULAR NUMBER: 6677 SUBJECT: GRB 070724B: Swift/UVOT Upper limits DATE: 07/07/28 15:46:01 GMT FROM: Margaret Chester at PSU M.M. Chester (PSU) and P. Romano (Uni-Bicocca and OAB) report on behalf of the Swift UVOT team: The Swift/UVOT observed the field of GRB 070724B (detected by SuperAGILE; Feroci et al., GCN Circ. 6668) beginning 2007-07-27 00:02:11 UT, 48.6 hours after the burst trigger time. We do not find any new source in any of the UVOT observations inside the refined Swift/XRT error circle for the likely candidate, source #1 (RA,DEC(J2000)= 17.48497, 57.67616, Romano et al., GCN Circ. 6675). We note a cataloged star, V=18.2, 7.6 arcsec from the XRT position. The 3-sigma upper limits for detecting a source inside the XRT error circle in the co-added frames are: Filter Tstart Tstop Exp Magnitude (s) (s) (s) (3-sigma UL) White 179270 197091 1776 21.3 v 175022 196602 2023 19.8 The values quoted above are not corrected for the expected Galactic extinction corresponding to a reddening of E_{B-V} = 0.51 mag in the direction of the burst (Schlegel et al. 1998).