TITLE: GCN CIRCULAR NUMBER: 25479 SUBJECT: GRB 190824A: Swift/UVOT Upper Limits DATE: 19/08/26 12:55:49 GMT FROM: Kira Simpson at PSU GRB 190824A: Swift/UVOT Upper Limits K. K. Simpson (PSU) and V. D'Elia (SSDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 190824A 568 s after the BAT trigger (D'Elia et al., GCN Circ. 25463). No optical afterglow consistent with the XRT position (Osborne et al., GCN Circ. 25466) 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 finding chart (FC) exposure and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 568 718 147 >19.9 white 568 1721 389 >19.9 v 1058 6747 196 >17.8 b 799 1697 97 >18.9 u 774 1672 97 >19.3 w1 750 1647 97 >18.4 m2 725 1622 97 >19.6 w2 849 1742 74 >18.7 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.12 in the direction of the burst (Schlegel et al. 1998).