GCN Circular 44924
Subject
IceCube-260610A: EP-FXT follow-up observation
Event
Date
2026-06-12T12:01:23Z (2 days ago)
From
EP Team at NAOC/CAS <ep_ta@bao.ac.cn>
Via
Web form
G. J. Yang, Q. Y. Wu and Y. Liu (NAO, CAS) on behalf of the Einstein Probe (EP) team:
EP-FXT conducted a follow-up observation of IceCube-260610A (GCN 44899), a Gold-track neutrino event. The observation began at 2026-06-10T21:56:33, approximately 1.9 hours after the neutrino trigger, with a total exposure of 7.9 ks.
Within the neutrino localization uncertainty region, none of the detected X-ray sources exhibited significant variability compared with their historical fluxes or upper limits. The properties of the detected sources, excluding those clearly associated with stars, are summarized below.
Name | RA | Dec | Flux (erg /cm^2 /s) | Flux error (erg /cm^2 /s) | SNR
EPF_J203646.2+370943 | 309.1926 | 37.1612 | 6.52e-14 | 1.71e-14 | 5.14
EPF_J203731.0+370929 | 309.3791 | 37.1577 | 5.66e-14 | 1.99e-14 | 4.72
EPF_J203711.7+370245 | 309.2994 | 37.0434 | 1.05e-13 | 2.00e-14 | 8.60
EPF_J203710.6+370109 | 309.2940 | 37.0191 | 5.46e-14 | 1.38e-14 | 6.10
EPF_J203748.1+370629 | 309.4505 | 37.1080 | 5.80e-14 | 1.54e-14 | 5.06
EPF_J203709.1+365818 | 309.2880 | 36.9716 | 6.02e-14 | 1.65e-14 | 4.40
EPF_J203803.5+371737 | 309.5105 | 37.2954 | 9.50e-14 | 2.40e-14 | 5.00
EPF_J203717.9+365622 | 309.3246 | 36.9393 | 5.75e-14 | 1.67e-14 | 4.24
EPF_J203730.0+373440 | 309.3750 | 37.5779 | 1.36e-13 | 5.01e-14 | 4.84
EPF_J203737.9+365019 | 309.4045 | 36.8384 | 7.51e-14 | 2.50e-14 | 4.75
EPF_J203835.0+364342 | 309.6481 | 36.7285 | 2.01e-13 | 4.98e-14 | 6.20
EPF_J203601.0+363247 | 309.0040 | 36.5464 | 2.38e-13 | 8.65e-14 | 3.60
We note that EPF_J203835.0+364342 is associated with a CV named ASASSN -16ix.
Additional follow-up observations are planned.