TITLE: GCN CIRCULAR NUMBER: 22649 SUBJECT: GRB 180418A: Swift-XRT observations DATE: 18/04/18 08:12:24 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), D.N. Burrows (PSU), J.A. Kennea (PSU), G. Cusumano (INAF-IASF PA), M. Perri (ASDC) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: The XRT began observing the field of GRB 180418A at 07:35:27.5 UT, 3081.4 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 170.12059, 24.93276 which is equivalent to: RA(J2000) = 11h 20m 28.94s Dec(J2000) = +24d 55' 57.9" with an uncertainty of 3.9 arcseconds (radius, 90% containment). This location is 88 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 1.07 x 10^20 cm^-2 (Willingale et al. 2013).