TITLE: GCN CIRCULAR NUMBER: 15267 SUBJECT: GRB 130925A: Swift/UVOT Detection of the Host Galaxy DATE: 13/09/27 18:22:43 GMT FROM: Stephen Holland at STScI S. T. Holland (STScI) reports on behalf of the Swift/UVOT team: Deep Swift/UVOT imaging taken between 157 s and 184.8 ks after the BAT trigger (Lien et al, 2013, GCNC 15246) shows a faint source at the location of the GROND detection (Sudilovsky et al. 2013, GCNC 15247). This source has a preliminary magnitude, on the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373), of white = 22.9 +/- 0.3 mag and is detected with a significance of 4.7 sigma. This magnitude has not been corrected for the expected extinction due to the Galactic reddening along the line of sight to this burst of E(B-V) = 0.02 mag (Schlafly et al. 2011, ApJS, 737, 103). The total white exposure time is 18 ks. There is no evidence for variability. The probability of finding a galaxy of this apparent luminosity within the UVOT-enhanced XRT error circle (Evans et al. 2013, GCNC 15251) is 0.01 using the method of Bloom et al. (2002, AJ, 423, 1111). The positional coincidence and lack of variability suggest that this is the host galaxy of GRB 130925A. There is no evidence in the UVOT data that this source has any extended structure.