TITLE: GCN CIRCULAR NUMBER: 16964 SUBJECT: GRB 141026A: Swift/UVOT Upper Limits DATE: 14/10/26 21:57:26 GMT FROM: Lea Hagen at PSU L. M. Z. Hagen (PSU) reports on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 141026A 166 s after the BAT trigger (Hagen et al., GCN Circ. 16950). No optical afterglow consistent with the XRT position (Beardmore et al. GCN Circ. 16956) or the likely optical afterglow (Littlejohns et al. GCN Circ. 16952, Varela et al. GCN Circ. 16953, Gorosabel et al. GCN Circ. 16954, Perley et al. GCN Circ. 16955, Butler et al. GCN Circ. 16962) 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 white (fc) 165 208 83 >19.98 white 3462 5667 688 >21.45 v 144 5962 290 >19.34 b 3826 5463 393 >20.48 u 3621 5258 393 >20.15 uvw1 4852 5052 196 >19.61 uvm2 4647 4847 196 >19.58 uvw2 4237 5873 393 >20.26 The magnitudes in the table are not corrected for the Galactic extinction due to the substantial reddening of E(B-V) = 0.19 in the direction of the burst (Schlegel et al. 1998).