Einstein Probe detects fast X-ray transient EP260728a with follow-up observations confirming uncatalogued X-ray source

AI Summary

EP-WXT detected a 70-second long transient event on 2026-07-28, followed by EP-FXT detecting an uncatalogued X-ray source with specific spectral properties. COLIBRÍ optical follow-up set an upper limit on potential optical counterparts.

Measurements

Notices (1)

Einstein Probe WXT — GRB · Tue, 28 Jul 2026 16:46:27 GMT

GCN Circulars (3)

GCN-45257 — EP260728a · Thu, 30 Jul 2026 10:16:03 GMT
The COLIBRÍ telescope, using the DDRAGO imager, observed the field of EP260728a and did not detect any new source at the FXT source position, setting an upper limit of z > 21.5. This observation was conducted approximately 37.2 to 38.6 hours after the trigger, with a total exposure time of 64 minutes.

GCN-45250 — EP260728a · Wed, 29 Jul 2026 07:40:29 GMT
The Einstein Probe (EP) performed a follow-up observation of the fast X-ray transient EP260728a, detecting an uncatalogued source with specific coordinates and spectral properties. The observation, conducted by EP-FXT, provided detailed spectral and flux measurements of the transient event.

GCN-45248 — EP260728a · Wed, 29 Jul 2026 02:47:29 GMT
The Einstein Probe mission detected a fast X-ray transient, designated EP260728a, on July 28, 2026. The event lasted approximately 70 seconds and was followed up by the Follow-up X-ray Telescope, which detected an uncatalogued X-ray source within the error circle.