TITLE: GCN CIRCULAR NUMBER: 8947 SUBJECT: GRB 090306B: Possible XRT afterglow DATE: 09/03/08 13:58:04 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Swift-XRT observed the field of the BAT Slew Survey burst GRB 090306B (Copete et al. GCN Circ. 8944) for 5.8 ks, from T0+67 ks to T0+81 ks. The data were entirely in PC mode. A single, faint source is found in the BATSS error circle, with a position RA,Dec = 231.2083, -6.9682 which is equivalent to: RA (J2000) = 15 24 49.99 Dec (J2000) = -06 58 05.6 with an uncertainty of 4.0 arcsec (radius, 90% confidence). We currently have only 16 counts from this source, at a count rate of 3.5 (+/- 0.9) e-3 counts s-1, and are unable to ascertain whether it is fading. Further observations, to verify the nature of this source, are planned. This circular is an official product of the Swift-XRT team.