Einstein Probe WXT detects X-ray transient EP261010a with optical follow-up

AI Summary

The Einstein Probe Wide-field X-ray Telescope (WXT) triggered on an uncatalogued X-ray transient at 2026-10-10T00:18:44 UTC with coordinates RA=26.236°, DEC=-34.09° and a 3 arcmin localization uncertainty. The source was detected in the 0.5-4 keV band with an image signal-to-noise ratio of 7.2 and a net count rate of 0.08 counts/s (derived from 20-min accumulated image). Follow-up observations with the FXT refined the position to 20 arcsec precision, and optical observations by MASTER-SAAO at 4266 seconds post-trigger yielded an upper limit of 16.2 mag in the clear filter, indicating no bright optical counterpart at that epoch.

Measurements

Notices (1)

Einstein Probe WXT — GRB · Sat, 10 Oct 2026 00:18:44 GMT

GCN Circulars (2)

GCN-45881 — EP261010a · Sat, 10 Oct 2026 02:00:44 GMT
The MASTER-SAAO robotic telescope in South Africa observed the error box of EP261010a 4266 seconds after the trigger time, setting an upper magnitude limit of 16.2 in the clear filter. The observations were conducted at a zenith distance of 31 degrees and a sun altitude of -30.9 degrees, with the galactic coordinates being b = -76 degrees and l = 246 degrees.

GCN-45880 — EP261010a · Sat, 10 Oct 2026 01:35:27 GMT
The Einstein Probe (EP) mission detected an X-ray transient, designated EP261010a, on October 10, 2026, at 00:18:44 UTC. A follow-up observation with the Follow-up X-ray Telescope (FXT) confirmed an uncatalogued X-ray source within the initial error circle.