TITLE: GCN CIRCULAR NUMBER: 11749 SUBJECT: GRB 110213B: Swift/UVOT observations DATE: 11/02/18 13:51:47 GMT FROM: Samantha Oates at MSSL S. R. Oates (MSSL-UCL) & R. Margutti, (INAF-OAB) reports on behalf of the Swift-UVOT team The Swift/UVOT began settled observations of the field of the MAXI GRB 110213B ~13hrs after the trigger (Negoro et al., GCN Circ. 11716). The optical afterglow detected by P60 (Cenko et al, GCN Circ. 11732, 11735) and GROND (Elliott et al, GCN Circ. 11743) only lies in the UVOT field of view for 3 images, one per filter (white, v and u) obseved at ~3 days after the trigger. Preliminary magnitudes using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) for the single exposures at the location of the optical afterglow are: Filter T_start(s) T_stop(s) Exp(s) 3sigUL ##################################################### wh 256170 256432 259 > 20.78 v 256438 256691 249 > 19.23 u 255901 256164 259 > 19.62 ##################################################### The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).