GCN Circular 42754

Subject

EP251118a: preliminary result of EP-FXT follow-up observation

Event

EP251118a

Date

2025-11-19T07:36:46Z (a day ago)

From

EP Team at NAOC/CAS <ep_ta@bao.ac.cn>

Via

Web form

R. Shi, Q. J. Huang, D. F. Hu (PMO, CAS), F. F. Song (YNAO, CAS), S. Q. Jiang (NAO, CAS), Q. C. Liu (THU), C. C. Jin (NAO, CAS) report on behalf of the Einstein Probe team:

The Follow-up X-ray Telescope (FXT) on board the Einstein Probe (EP) performed one ToO observation for EP251118a, starting at 2025-11-19T04:02:14 (UTC). Within the WXT error circle, an uncatalogued X-ray source was detected at R.A. = 123.1677 deg, DEC = 10.9364 deg (J2000) with an uncertainty of 20 arcsec in radius (90% C.L. statistical and systematic). The position is consistent with the optical counterpart reported before (Malesani et al. GCN 42751) with a seperation of 14.75 arcsec.

Further information will be updated when the telemetry data is received.

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).