TITLE: GCN CIRCULAR NUMBER: 43822 SUBJECT: EP260223a: EP-FXT follow-up observation DATE: 26/02/25 04:06:11 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> Q. C. Liu (THU), J. W. Hu and H. Sun (NAO, CAS) on behalf of the Einstein Probe (EP) team:   We performed one follow-up observation of the X-ray transient EP260223a (Liu et al., GCN 43817, and followed by Álvarez et al., GCN 43818) with the Follow-up X-ray Telescope (FXT) on board the Einstein Probe (EP) mission. The observation started at 2026-02-24 04:45:40 (UTC), about 17.42 hours after the WXT detection, with an exposure of ~5.2 ks. No source was detected within the WXT error circle. The 0.5-10 keV flux upper limit is about 6e-14 erg/s/cm^2 (90% C. L.).   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). View this GCN Circular online at https://gcn.nasa.gov/circulars/43822. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...