TITLE:   GCN CIRCULAR
NUMBER:  35723
SUBJECT: GRB 240128A: Further Swift-XRT observations
DATE:    24/02/14 07:52:22 GMT
FROM:    Paolo D'Avanzo at INAF-OAB <pda.davanzo@gmail.com>

P. D'Avanzo (INAF-OAB), K.L. Page (U. Leicester) and P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:

Swift-XRT has performed further follow-up observations of the MAXI-detected burst GRB 240128A (Yamaoka et al., GCN Circ. 35646; 
Yoshida et al., GCN Circ. 35647; Dafcikova et al., GCN Circ. 35649; Cheung et al., GCN Circ. 35651). The data were collected between T0+553.6 ks and T0+1237.1 ks, and are entirely in Photon Counting (PC) mode for a total exposure time of 8.0 ks. 

The uncatalogued X-ray source reported by Perri et al. ("Source 1"; GCN Circ. 35650), is still detected at an average count rate of 
~ 4e-2 ct/s and shows no definitive signs of fading. Therefore, we conclude that it is likely a field source unrelated with the GRB. 

The results of the XRT-team automatic analysis of the XRT observations for this GRB, including a position-specific upper limit calculator, 
are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00120 <https://www.swift.ac.uk/xrt_products/TILED_GRB00120>.

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