TITLE: GCN CIRCULAR NUMBER: 32252 SUBJECT: GRB 220623A: Swift/UVOT Upper Limits DATE: 22/06/23 18:32:09 GMT FROM: Alexander Belles at PSU/Swift A. Belles (PSU) and B. Sbarufatti (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 220623A 4034 s after the BAT trigger (Sbarufatti et al., GCN Circ. 32243). No optical afterglow consistent with the XRT position (Kennea et al. GCN Circ. 32244) 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 4034 4184 147 >19.9 white 4034 5415 344 >20.1 v 4190 9642 326 >18.9 b 5010 5210 197 >19.4 u 4805 5005 197 >19.0 w1 4600 4800 197 >19.3 m2 4395 4595 197 >19.9 w2 5421 5621 197 >19.6 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.036 in the direction of the burst (Schlegel et al. 1998).