TITLE: GCN CIRCULAR NUMBER: 20045 SUBJECT: GRB 161014A: Swift/UVOT Detection DATE: 16/10/15 10:59:41 GMT FROM: Samantha Oates at MSSL S. R. Oates (U. of Warwick) and J. L. Racusin (NASA/GSFC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 161014A 4 ks after the BAT trigger (Racusin et al., GCN Circ. 20035). A source consistent with the optical position reported by MITSuME (Morita et al GCN Circ 20036) and LCOGT-FTS (Guidorzi et al., GCN Circ. 20037) is detected in the initial UVOT exposures. The lack of detection in the u and UV bands is consistent with the redshift of 2.823 reported by GTC (de Ugarte Postigo et al., GCN Circ. 20043). The preliminary UVOT position is: RA (J2000) = 22:10:35.46 = 332.64775 (deg.) Dec (J2000) = 7:28:07.3 = 7.46869 (deg.) with an estimated uncertainty of about 0.9 arc sec. (radius, 90% confidence). Preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are: Filter T_start(s) T_stop(s) Exp(s) Mag wh 4491 4690 197 20.4 +/- 0.3 wh 5929 6129 197 > 20.85 v 4903 5103 197 19.1 +/- 0.4 b 4286 5924 393 20.3 +/- 0.3 u 4081 23870 1630 > 20.9 w1 5314 23503 1968 > 21.0 m2 5109 18128 1163 > 20.8 w2 4698 6335 393 > 20.2 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.08 in the direction of the burst (Schlegel et al. 1998).