TITLE: GCN CIRCULAR NUMBER: 15489 SUBJECT: GRB 130925A: HST imaging DATE: 13/11/16 09:22:23 GMT FROM: Nial Tanvir at U.Leicester N. R. Tanvir (U. Leicester), A. J. Levan (U. Warwick), R. Hounsell, A. S. Fruchter (STScI), S. B. Cenko (NASA/GSFC), D. A. Perley (Caltech), P. T. O'Brien (U. Leicester) report: We imaged the location of GRB 130925A (Evans et al. GCN 15251; Sudilovsky et al. GCN 15247) with HST at two epochs, at 20 days and 47 days post-burst respectively, in the F814W (I-band), F110W (J-band) and F160W (H-band) filters. The host galaxy is well resolved and appears to be an almost edge-on spiral. The galaxy shows signs of disturbance: specifically the disk shows asymmetry and the bulge appears to be extended perpendicular to the disk, suggestive of a polar-ring morphology. Image subtraction reveals evidence of faint transient light in the first epoch in all three filters. The location is in good agreement with that from prior ground-based imaging of the GRB. The transient position is close to the disk plane, which likely accounts for the high extinction and X-ray column for this event (Evans et al. GCN 15254). It is, however, slightly offset from the nucleus of the galaxy by about 0.12 arcsec (~600pc in projection). This would initially seem to be in conflict with a possible tidal disruption origin for this event, although if the galaxy morphology is indicative of a recent major merger, then it is plausible that the system currently contains more than one super-massive black hole. Further analysis is ongoing. We thank the staff at STScI for approving and expediting these ToO observations.