TITLE: GCN CIRCULAR NUMBER: 20691 SUBJECT: GRB 170214A: Swift-XRT afterglow detection DATE: 17/02/18 02:47:32 GMT FROM: Andy Beardmore at U Leicester A.P. Beardmore (U. Leicester), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), A. Cholden-Brown (PSU), S. J. LaPorte (PSU), J.A. Kennea (PSU), S.L. Gibson (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has conducted further observations of the field of the Fermi/LAT-detected burst GRB 170214A. The observations now extend from T0+38.6 ks to T0+274.4 ks. Of the sources previously reported, "Source 1" is above the RASS limit and fading with 3-sigma significance, and is therefore likely the GRB afterglow. Using 4445 s of PC mode data and 4 UVOT images, we find an enhanced XRT position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 256.34147, -1.88746 which is equivalent to: RA (J2000): 17h 05m 21.95s Dec(J2000): -01d 53' 14.9" with an uncertainty of 2.4 arcsec (radius, 90% confidence). This position is 49 arcsec from the Fermi/LAT position. The source is fading with alpha >0.7. The results of the XRT-team automatic analysis of the likely afterglow are at http://www.swift.ac.uk/ToO_GRBs/00020740/index_1.php. The results of the full analysis of the XRT observations are available at http://www.swift.ac.uk/ToO_GRBs/00020740. This circular is an official product of the Swift-XRT team.