TITLE: GCN CIRCULAR NUMBER: 7421 SUBJECT: Swift/UVOT observations of GRB 080315 DATE: 08/03/15 21:36:41 GMT FROM: Patricia Schady at MSSL/Swift P. Schady (MSSL/UCL) and K. L. Page (U Leicester) report on behalf of the Swift UVOT team: The Swift/UVOT observed the field of GRB 080315 starting 125 s after the BAT trigger (Page et al., GCN 7416). We do not find any source in any of the individual or co-added exposures, either within the BAT error circle or at the location of the weak source detected by XRT (Barthelmy et al. GCN 7420). The 5-sigma upper limits for detecting a source at the position of the XRT candidate in the co-added images are: Filter T_start T_stop Exp Mag (s) (s) (s) (5-sigma upper limit) ----------------------------------------------------- v 127 42160 6078.4 > 20.79 b 608 40422 5815.6 > 21.84 u 582 7467 620.7 > 20.30 uvw1 558 7281 468.7 > 19.82 uvm2 533 7075 858.7 > 20.00 uvw2 113 41328 5847.3 > 21.63 ----------------------------------------------------- The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight corresponding to a reddening of E(B-V) = 0.01 mag. All photometry is on the UVOT light flight system described in Poole et al. (2008, MNRAS, 383, 627).