TITLE: GCN CIRCULAR NUMBER: 41650 SUBJECT: GRB 250901A: EP-FXT follow-up observation DATE: 25/09/02 04:04:05 GMT FROM: EP Team at NAOC/CAS <ep_ta@bao.ac.cn> H. N. Yang (NAO, CAS), Z. Y. Liu (USTC), Y. J. Zhang (THU), C. C. Jin (NAO, CAS) report on behalf of the Einstein Probe (EP) team: EP-FXT performed a follow-up observation of GRB 250901A (GCN 41634) at 2025-09-01T20:03:51 (UTC), about 2 hours after the SVOM/ECLAIRs detection, with an exposure time of 5 ks. The source was also followed by Swift-XRT (GCN 41645). The optical afterglow was also detected by SVOM/VT (GCN 41646). FXT detected an uncatalogued source at R.A. = 356.1845, DEC = -15.7418 (J2000) with an uncertainty of 10 arcsec (radius, 90% C.L. statistical and systematic), consistent with the position of the source reported by Swift/XRT (offset is 4.0 arcsec). The FXT spectrum of this source can be fitted with an absorbed powerlaw with the absorption fixed at the Galactic value of 1.7x10^20 cm^-2, and a photon index of 1.97(+/-0.16). The derived unabsorbed 0.5-10 keV flux is approximately 2.4(+/-0.3)x10^-12 erg/s/cm2. The uncertainties are at the 90% confidence level for the above parameters. 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/41650. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...