TITLE: GCN CIRCULAR NUMBER: 9678 SUBJECT: GRB 090715B: Swift/UVOT followup observations DATE: 09/07/16 12:32:09 GMT FROM: Alice Breeveld at MSSL-UCL A. Breeveld (MSSL/UCL) and L. Vetere (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 090715B 53 s after the BAT trigger (Vetere et al., GCN Circ. 9668). The optical afterglow reported in Vetere et al., GCN 9668 and confirmed by Smith et al., GCN 9670, Malesani et al., GCN 9671, Wiersema et al., GCN 9673 and Antonelli et al., GCN 9675 is detected by the UVOT only in the initial white exposure. The detected magnitude and preliminary 3-sigma upper limits obtained using a 3" aperture and the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the first finding chart (FC) exposure and subsequent summed exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 53 203 147 20.37 +/- 0.15 white 4052 4252 196 >21.3 v 5989 22687 795 >21.0 b 3848 4047 197 >20.3 u 266 16495 428 >21.2 w1 12053 16278 894 >21.2 m2 6195 10367 826 >21.0 w2 4258 22065 995 >21.4 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.01 in the direction of the burst (Schlegel et al. 1998).