GCN Circular 31917
M. H. Siegel and J. D. Gropp (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 220412B 89 s after the BAT trigger (Gropp et al., GCN Circ. 31886). No optical afterglow consistent with the BAT position (Sakamoto et al., GCN Circ. 31910) 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) 89 217 128 >20.0 white 4378 4577 197 >20.3 b 4173 4373 197 >19.8 u 3968 4167 197 >19.4 w2 4584 4663 78 >19.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.060 in the direction of the burst (Schlegel et al. 1998).