GCN Circular 44539
Subject
EP260509a: EP-FXT non-detection and upper limit
Event
Date
2026-05-11T09:39:15Z (3 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
S.-Y. Fu (HUST), A. Li (BNU), C.-Y. Wang (THU), R. Shi (PMO), Y. Liu (NAOC, CAS) on behalf of the Einstein Probe (EP) team:
EP-FXT observed the field of EP260509a (detected by EP-WXT, Wang et al., GCN 44517; and followed by MASTER-Net observations, Lipunov et al., GCN 44525) for 5475 seconds starting at 2026-05-10T10:15:44, around 20.5 hours after the detection by EP-WXT. No significant X-ray source is detected within the 2.78 arcmin radius of the EP-WXT position (Wang et al., GCN 44517) to a preliminary 0.5-10 keV upper limit of 3e-14 erg/cm2/s.
Launched on January 9, 2024, EP is a space X-ray observatory to monitor the soft X-ray sky with X-ray follow-up capability (Yuan et al. 2022, Handbook of X-ray and Gamma-ray Astrophysics).