TITLE:   GCN CIRCULAR
NUMBER:  30622
SUBJECT: GRB 210802A: Further Swift/XRT observation and afterglow confirmation
DATE:    21/08/09 13:55:33 GMT
FROM:    Valerio D'Elia at ASDC  <valerio.delia@ssdc.asi.it>

V. D'Elia (ASI-SSDC & INAF-OAR) and S.B. Cenko (GSFC) report on behalf of the Swift-XRT team:


Swift-XRT has performed further follow-up observations of the Fermi burst (Longo et al., GCN Circ. 30589; Roberts et al., GCN Circ. 30590).

The possible afterglow reported in Sbarufatti et al. (GCN Circ. 30591, "source 7") is no longer detected in a 4 ks observation, down to a three sigma upper limit of 4.8E-3 cts/s (corresponding to 1.28E-13 erg/cm^2/s) at the position of the transient. This value is significantly below the previously reported flux value for the candidate, thus confirming “source 7” as the afterglow of GRB 210802A.

The results of the full analysis of the XRT observations are available at https://www.swift.ac.uk/xrt_curves/00021456/.

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