GCN Circular 37461
Subject
GRB 240910A: Swift-XRT detection of GOTO24fvl/AT2024vfp
Date
2024-09-11T20:32:11Z (3 months ago)
From
Phil Evans at U of Leicester <pae9@star.le.ac.uk>
Via
email
A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), D.N. Burrows (PSU), M. A.
Williams (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U.
Leicester), 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 240910A (GCN Circ. 37441), centred on the
position of the candidate optical counterpart detected by GOTO:
GOTO24fvl/AT2024vfp (Julakanti et al., GCN Circ. 37459). XRT has
collected 1.9 ks of Photon Counting (PC) mode data between T0+128.3 ks
and T0+135.2 ks.
An uncatalogued X-ray source is found at the GOTO position. Its current
flux is below historical upper limits and we cannot currently confirm
fading; thus, based on X-ray data alone we cannot identify this as a
transient. However, given its coincidence with the GOTO source, we
suggest that is it likely to be the GRB afterglow.
Details of this source are given below:
Source 2:
RA (J2000.0): 24.0972 = 01:36:23.32
Dec (J2000.0): -0.2047 = -00:12:17.1
Error: 4.0 arcsec (radius, 90% conf. [Enhanced position])
Count-rate: 0.0182 +/- 0.0042 ct s^-1
Distance: 2 arcsec from GOTO position.
Flux: (7.3 +/- 1.7)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
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/00021712.
This circular is an official product of the Swift-XRT team.