TITLE: GCN CIRCULAR NUMBER: 16662 SUBJECT: GRB 140801A: Swift/UVOT Upper Limits DATE: 14/08/02 18:10:39 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) and E. Troja (NASA/GSFC/UMCP) report on behalf of the Swift/UVOT team: The Swift/UVOT observed the field of the Fermi/GBM-detected burst GRB 140801A beginning 36.4 ks after the trigger (Pelassa, GCN Circ. 16658). No optical afterglow consistent with the XRT candidate (Maselli, GCN Circ. 16661) or MASTER candidate (Gorbovskoy et al., GCN Circ. 16653) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag uvw1 36391 47996 1944 >20.70 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.226 in the direction of the burst (Schlegel et al. 1998).