GCN Circular 38867
Subject
EP250109a: Swift/XRT non-detection
Date
2025-01-09T12:12:58Z (8 days ago)
From
Jamie Kennea at Penn State <jak51@psu.edu>
Via
Web form
J. A. Kennea (PSU) and P. A. Evans (Leicester) on behalf of the Swift XRT Team report:
On 09:19:41UT Swift XRT began a 950s exposure of the field containing the recently reported transient EP250109a (GCN #38864), 3 hours after detection by Einstein Probe WXT. Examination of the XRT data does not reveal any new X-ray sources, with an upper limit on count rate of 0.01 c/s at the EP FXT position. For a typical GRB-like spectrum this equates to an upper limit on flux of 3 x 10^-13 erg/s/cm^2 (0.3-10 keV).
Although GCN #38864 does not report flux, the Swift/XRT non-detection suggests that this transient has rapidly faded.