TITLE:   GCN CIRCULAR
NUMBER:  42075
SUBJECT: GRB 251002A: EP-FXT counterpart detection
DATE:    25/10/03 06:02:41 GMT
FROM:    EP Team at NAOC/CAS <ep_ta@bao.ac.cn>


X. X. Sun(NAO,CAS), Y.Q. Zhao(USTC,PRIC), Y. L. Wang (NAO, CAS; ICE, CSIC-IEEC)，and Z. X. Ling (NAO, CAS) on behalf of the Einstein Probe (EP) team:
 
EP-FXT performed a follow-up observation of the SVOM/ECLAIRs-detected burst GRB 251002A (SVOM/sb25100211, Saccardi et al. GCN 42060) at 2025-10-02T20:52:13Z (UTC), 2239 seconds after the SVOM/ECLAIRs trigger, with an exposure time of 2918s. One uncatalogued source is detected within the ECLAIRs error circle, and the source is spatially consistent with the counterpart reported in optical bands (Palmerio et al. GCN 42061, Turpin et al. GCN 42062, Jelinek et al. GCN 42063, Juliá-Maroto et al. GCN 42064, Moskvitin et al. GCN 42065，Perez-Garcia et al. GCN 42066, Senik et al. GCN 42067). Preliminary analysis on this source are automatically conducted, and details are listed as follows.
 
Source 1: EPF_J005537.9-053402
RA(J2000): 13.9078
Dec (J2000): -5.5669
Flux: 1.295e-11 erg/s/cm2 (observed, 0.5-10 kev)
Flux_err: 7.6399e-13 erg/s/cm2 (1 sigma)
 
The position uncertainty of the source is about 10 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).