GCN Circular 43558
Subject
GRB 260127B: Swift-XRT observations
Event
Date
2026-01-29T15:59:58Z (2 days ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
D.N. Burrows (PSU), S. Lanava (PSU), S. Dichiara (PSU), J.P. Osborne
(U. Leicester), K.L. Page (U. Leicester), S. Campana (INAF-OAB), A.
Melandri (INAF-OAR), T. Sbarrato (INAF-OAB) and P.A. Evans (U.
Leicester) reports on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Fermi/GBM-detected burst GRB 260127B (The Fermi GBM team, GCN Circ.
43533), collecting 985 s of Photon Counting (PC) mode data between
T0+70.4 ks and T0+71.4 ks.
No X-ray sources have been detected consistent with the tentative GOTO
optical afterglow candidate (O’Neill et al, GCN Circ. 43538). The
3-sigma upper limit in the field ranges from ~0.01 to ~0.02 ct s^-1,
corresponding to a 0.3-10 keV observed flux of 5.0e-13 to 6.9e-13 erg
cm^-2 s^-1 (assuming a typical GRB spectrum).
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
https://www.swift.ac.uk/ToO_GRBs/00021900.
This circular is an official product of the Swift-XRT team.