TITLE: GCN CIRCULAR NUMBER: 22898 SUBJECT: GRB 180703A: Swift/UVOT Upper Limits DATE: 18/07/04 17:04:13 GMT FROM: Sam Emery at MSSL-UCL S.W.K. Emery (UCL-MSSL) and E. Sonbas (Adiyaman Univ.) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 180703A 17269 s after the Fermi/LAT trigger (Racusin et al. GCN Circ. 22883). No optical afterglow consistent with the XRT position of the uncatalogued X-ray source, source 1 (Gibson et al. GCN Circ. 22891) or the position from LCO Sutherland (Guidorzi et al. GCN Circ. 22892) 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 first exposures at the position of source 1 are: Filter T_start(s) T_stop(s) Exp(s) Mag b 17353 28862 47 >19.2 u 17323 28834 116 >19.5 uvw1 17269 28807 234 >19.8 uvw2 17384 28917 97 >19.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998).