TITLE:   GCN CIRCULAR
NUMBER:  36721
SUBJECT: GRB 240619A: Swift-XRT probable afterglow detection
DATE:    24/06/21 08:07:00 GMT
FROM:    Phil Evans at U of Leicester <pae9@star.le.ac.uk>

M. Capalbi (INAF-IASFPA), M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC &
INAF-OAR), S. Dichiara (PSU), J.A. Kennea (PSU), A. Tohuvavohu (U.
Toronto), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester)
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 240619A (GCN Circ. 36694), collecting 1.7
ks of Photon Counting (PC) mode data between T0+174.0 ks and T0+175.7
ks at the location of the GOTO afterglow candidate AT 2024lwv (Gompertz
et al., GCN Circ. 36715).

An uncatalogued X-ray source is detected at RA, Dec=162.3944, +17.2829
which is equivalent to:

RA (J2000): 10:49:34.66
Dec(J2000): +17:16:58.5

with an uncertainty of 4.3 arcsec (radius, 90% confidence).  This
position is 0.7 arcsec from the GOTO position and thus we suggest it is
related to that object and likely the GRB afterglow.  The source has a
mean count rate of 2.5e-02 ct/sec; we cannot determine at the present
time whether it is fading.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00021697.
The results of the full analysis of the XRT observations are available
at https://www.swift.ac.uk/ToO_GRBs/00021697.

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