GCN Circular 39482
Subject
EP250226a/GRB 250226A: EP-WXT detection and FXT follow-up observation of an X-ray transient
Date
2025-02-26T07:30:36Z (12 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
S. Q. Jiang (NAO, CAS), B.-T. Wang (YNAO, CAS), H. Z. Wu (HUST), T. Zhao, Y.J. Song, Y. Liu (NAO, CAS) report on behalf of the Einstein Probe team:
We report on the detection of an X-ray transient EP250226a at 2025-02-26 06:35:16 (UTC) by the Wide-field X-ray Telescope (WXT) on board the Einstein Probe (EP) mission. The WXT position of the source is R.A. = 224.273 deg, DEC = 20.973 deg (J2000) with an uncertainty of 3 arcmin in radius (90% C.L. statistical and systematic). The trigger time and the position are generally consistent with the likely long GRB 250226A detected by Fermi (GCN 39479).
A follow-up observation with the Follow-up X-ray Telescope (FXT) was performed automatically. Within the WXT error cirlce, an uncatalogued X-ray source was detected at R.A. = 224.2668 deg, DEC = 20.9743 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic).
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).