TITLE:   GCN CIRCULAR
NUMBER:  45652
SUBJECT: EP260917b: EP-FXT non-detection and upper limit
DATE:    26/09/20 04:06:01 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

B. Zhang, J. P. Feng (USTC), G. Y. Zhao (QTNU), Z.-C. Zou (NJU), W. D. Zhang (NAO,CAS) on behalf of the Einstein Probe (EP) team: 

EP-FXT performed a follow-up observation of EP260917b (Zhang et al., GCN 45629) starting at 2026-09-19T07:09:10 (UTC), approximately 40 hours after the WXT detection. With an exposure time of 2961s, no significant X-ray source was detected within the 2.6 arcmin radius of the EP-WXT position. The derived 0.5-10 keV upper limit is about 3.32e-14 erg cm^-2 s^-1.

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).