General information
EP260329b is a fast X-ray transient detected by Einstein Probe/WXT (trigger 01709259209) at 2026-03-29 10:36:00 UTC (refined T0=10:35:25), with an uncatalogued X-ray source confirmed by EP/FXT and an optical counterpart detected by multiple facilities.
Wavelength coverage
- X-ray: EP/WXT trigger and refined 0.5–4 keV spectral/flux analysis; EP/FXT follow-up detection with temporal structure and 0.5–10 keV spectral/flux analysis.
- Optical: Detections in w, r, z, and GOTO L-band; additional clear/C imaging limits and later deeper R/r' upper limits.
- Near-IR: WINTER J-band non-detection with a 5-sigma upper limit.
Bands with no observations mentioned: gamma-ray, UV, radio, mm/sub-mm.
Lightcurve and spectrum
Redshift
What’s special vs typical
GCN 44173: EP260329b: Mondy and Assy-Turgen optical upper limits
2026-04-01T09:25:28.469Z | rev 0
GCN 44169: EP260329b: GOTO detection of optical counterpart
2026-03-31T17:39:44.294Z | rev 0
GCN 44163: EP260329b: J-band upper limits with WINTER
2026-03-31T00:28:16.998Z | rev 0
GCN 44155: EP260329b: refined analysis of the EP-WXT and EP-FXT observations
2026-03-30T13:25:23.390Z | rev 0
GCN 44155: EP260329b: refined analysis of the EP-WXT and EP-FXT observations
2026-03-30T13:25:23.390Z | rev 2
GCN 44150: EP260329b: Global MASTER-Net observations report
2026-03-29T23:45:30.728Z | rev 0
GCN 44147: EP260329b: Optical follow-up with Kinder observations
2026-03-29T14:47:29.115Z | rev 0
GCN 44146: EP 260329b: COLIBRÍ optical observations
2026-03-29T14:45:02.472Z | rev 0
GCN 44144: EP260329b: LCO optical observations of the counterpart
2026-03-29T13:42:38.324Z | rev 0
GCN 44142: EP260329b: Einstein Probe detection of an X-ray transient
2026-03-29T12:07:29.886Z | rev 0
GCN 44142: EP260329b: Einstein Probe detection of an X-ray transient
2026-03-29T12:07:29.886Z | rev 2
GCN 44139: The EP-WXT trigger 01709259209 (EP260329b?): Las Cumbres discovery of the optical counterpart
2026-03-29T11:11:13.294Z | rev 0