TITLE: GCN CIRCULAR NUMBER: 8028 SUBJECT: GRB 080727A: Swift-XRT refined analysis DATE: 08/07/27 15:30:20 GMT FROM: Kim Page at U.of Leicester K.L. Page, J.P. Osborne (U. Leicester) and S. Immler (CRESST/GSFC/UMD) report on behalf of the Swift-XRT team: We have analysed the first three orbits of data obtained for GRB 080727A (Immler et al., GCN Circ. 8021), covering 7 ks of Photon Counting mode data. The UVOT-enhanced position has been given by Evans et al. (GCM Circ. 8025). During the first orbit (117s - 1.9 ks after the trigger), the light-curve shows a number of small flares, superimposed on a power-law decay of alpha= 2.01 +0.18/-0.17. The source is no longer detected in the combined second and third orbits of data (5.3 ks of exposure time, starting 5 ks after the trigger). Although the upper limit is consistent with the continued decay of alpha = 2.01, it is not possible to determine whether a break has occurred. The spectrum from the first orbit of data can be fitted with a power-law of Gamma = 1.43 +0.20/-0.19, absorbed by the Galactic column in this direction (6.75x10^20 cm^-2). The average observed (unabsorbed) flux over this time is 5.56 (6.02) x 10^-12 erg cm^-2 s^-1. The counts to observed flux conversion is 5.3 x 10^-11 erg cm^-2 count^-1. With the limited information available from a detection only in the first orbit, we are unable confidently to predict the flux at 24 hours. This is an official product of the Swift-XRT team.