TITLE: GCN CIRCULAR NUMBER: 7877 SUBJECT: GRB080613B: Swift/UVOT Upper Limits DATE: 08/06/13 22:13:41 GMT FROM: Wayne Landsman at GSFC/SSAI W.Landsman (GSFC/Adnet) and C. Markwardt (CRESST/GSFC/UMD) , on behalf of the Swift/UVOT team. The Swift Ultra-Violet/Optical Telescope (UVOT) began settled observations of GRB 080613B (trigger 313954) 79 seconds after the BAT trigger (Markwardt et al.,GCN Circ. 7873). No afterglow is detected at the enhanced XRT position (Mao et al., GCN Circ.7875) in the initial white finding chart or subsequent summed images. The limiting magnitudes (3-sigma in 5" radius apertures) in each of the UVOT filters are as follows: Filter T_start(s) T_stop(s) Exp(s) Mag UL (3sig) white 79 180 98 >20.4 white 79 7227 627 >21.4 v 185 7566 1167 >20.1 b 665 7023 451 >20.5 u 640 13348 312 >20.1 uvw1 616 13323 1179 >20.8 uvm2 591 12415 1102 >21.2 uvw2 695 18103 936 >21.0 The values quoted above are in the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627). They are not corrected for the expected Galactic extinction corresponding to a reddening of E(B-V)=0.04 mag in the direction of the burst (Schlegel et al. 1998).