GCN Circular 45407
Subject
GRB 260818B: EP-FXT follow-up observation
Event
Date
2026-08-20T05:17:32Z (3 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
Q. Y. Wu (NAO, CAS), H. Zhou, Y. L. Hua (PMO, CAS), W. D. Zhang (NAO, CAS) on behalf of the Einstein Probe (EP) team:
EP-FXT performed a follow-up observation of GRB 260818B detected by SVOM/ECLAIRs (Cordier et al., GCN 45398). The observation started at 2026-08-18 22:01:25(UTC), about 1.84 hr after the SVOM trigger, with a total exposure time of around 6.0 ks.
On-ground analysis of the FXT data found several uncataloged sources inside the ECLAIRs error region
Name | RA | DEC | Sep_obj (arcmin) | Flux (erg/cm^2/s)
EPF_J025951.6+072917 | 44.9651 | 7.4881 | 2.47 | 4.4e-14
EPF_J025955.0+072535 | 44.9791 | 7.4263 | 2.85 | 4.5e-14
EPF_J025936.6+072418 | 44.9024 | 7.4049 | 3.76 | 1.5e-12
EPF_J025950.9+073127 | 44.9619 | 7.5242 | 4.36 | 9.8e-14
with uncertainties of 10 arcsec (radius, 90% C.L. statistical and systematic). None of these sources showed significant variability during this observation.
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).