TITLE: GCN CIRCULAR NUMBER: 30745 SUBJECT: GRB 210827A: further Swift-XRT observations DATE: 21/08/30 13:34:23 GMT FROM: Paolo D'Avanzo at INAF-OAB pda.davanzo@gmail.com

P. D'Avanzo, M. G. Bernardini, A. Melandri, T. Sbarrato (INAF-OAB), P. A. Evans (U. Leicester) report on behalf of the Swift team:

Swift-XRT has performed further follow-up observations of the Swift/BAT-GUANO-detected burst GRB 210827A (James DeLaunay et al. GCN Circ. 30732), collecting a total of 12.2 ks of Photon Counting (PC) mode data between T0+44.4 ks and T0+257.2 ks. The uncatalogued candidate X-ray source (Source 3) reported in Gropp et al. (GCN Circ. 30734) faded to a count-rate of 3e-3 ct s^-1, thus suggesting it as the likely X-ray afterglow of GRB 210827A. The light curve can be described with a single power-law with a decay index alpha = 1.0 (+0.5, -0.4).

The results of the XRT-team automatic analysis are available at https://www.swift.ac.uk/xrt_products/00021461 https://www.swift.ac.uk/xrt_products/00021461

This circular is an official product of the Swift-XRT team.