TITLE: GCN CIRCULAR NUMBER: 31005 SUBJECT: GRB 211024B: Swift/UVOT detection DATE: 21/10/26 13:13:02 GMT FROM: Paul Kuin at MSSL <npkuin@gmail.com> N. P. M. Kuin (UCL-MSSL) and J. Gropp (PSU) reports on behalf of the Swift/UVOT team: We report here the early Swift/UVOT photometry of GRB 211024B (Gropp et al., GCN Circ. 30980; Zhu et al. GCN Circ. 30984; Lien et al. GCN Circ 30989; Evans et al. GCN Circ 30994; Kann et al. GCN Circ. 30995) at the position reported by Zhu et al. (GCN Circ. 30984). Preliminary detections using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the early exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag v 6237 6437 197 19.2 +/- 0.4 v 12395 24343 1665 20.4 +/- 0.4 b 5826 5927 197 20.0 +/- 0.4 u 5621 5821 197 18.8 +/- 0.2 u 6852 7052 197 19.3 +/- 0.3 w1 6647 6847 197 19.2 +/- 0.3 m2 6442 6642 197 19.3 +/- 0.3 w2 6032 6232 197 20.1 +/- 0.5 w2 7260 7360 98 19.5 +/- 0.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening in the direction of the burst.