GCN Circular 16661
A. Maselli and M. De Pasquale (INAF-IASFPA) report on behalf of the Swift-XRT team: We have analysed 2.0 ks of XRT data for the FERMI/GBM detected burst GRB 140801A (Pelassa, GCN Circ. 16658), from 36.4 ks to 48.0 ks after the GBM trigger. The data are entirely in Photon Counting (PC) mode. An X-ray source is found at the position of the optical transient detected by MASTER (Gorbovskoy et al., GCN Circ. 16653). Using 1893 s of PC mode data and 2 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 = 44.06877, +30.93799 which is equivalent to: RA (J2000): 02h 56m 16.50s Dec(J2000): +30d 56' 16.8" with an uncertainty of 2.5 arcsec (radius, 90% confidence). This position is 0.8 arcsec from the MASTER position. We believe that this source, which has a mean count rate of 2.3e-02 ct/sec, is the X-ray afterglow of GRB 140801A but further observations are needed to determine a decaying behaviour. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020402. This circular is an official product of the Swift-XRT team.