TITLE: GCN CIRCULAR NUMBER: 17836 SUBJECT: GRB 150518A: Swift-XRT follow-up observations DATE: 15/05/21 08:07:23 GMT FROM: Claudio Pagani at U of Leicester C. Pagani (U. Leicester) reports on behalf of the Swift team: A second epoch of XRT data was collected on the field of the MAXI-detected burst: GRB 150518A (Kawamuro et al., GCN Circ. 17825) on 2015 May 20. The observations consist of 5 ks of PC mode data, from T0+146 ks to T0+154 ks. The X-ray source reported in GCN Circ. 17827, Sbarufatti et al., measured at a mean count rate of 3.4 x 10^-1 count s^-1 (0.3-10 keV) in the first epoch of XRT observations has faded with a power law decay index of alpha=1.04 +/- 0.11 to a mean count rate of 3.1 x 10^-2 count s^-1 (0.3-10 keV) in the second epoch. We therefore confirm that this is the X-ray afterglow of GRB 150518A. This circular is an official product of the Swift-XRT team.