General information
EP260618a is an EP-triggered high-energy transient with optical follow-up reported by OHP/T193 and the Liverpool Telescope; the text also references a Fermi GBM circular. Both provided circulars report detection of the optical counterpart at the position of earlier counterpart reports.
Wavelength coverage
- Optical: OHP/T193 MISTRAL obtained 2x10 min r-band imaging starting 2026-06-18T21:12:40 UT, 12.63 hr after trigger, measuring r = 21.86 +/- 0.09 AB.
- Optical: Liverpool Telescope IO:O obtained SDSS griz imaging starting 2026-06-19 02:32:19 UT, about 17.96 hr after the EP trigger, detecting the source in all filters with g = 22.47 +/- 0.24, r = 22.03 +/- 0.12, i = 21.62 +/- 0.11, and z = 21.48 +/- 0.26 AB.
Bands with no observations mentioned in the provided circulars: radio, millimeter, infrared, ultraviolet, X-ray, gamma-ray properties, neutrino, and gravitational waves.
Lightcurve and spectrum
- At 12.63 hr after trigger, OHP/T193 measured r = 21.86 +/- 0.09 AB.
- At 18.08-18.88 hr after trigger, Liverpool Telescope measured g = 22.47 +/- 0.24, r = 22.03 +/- 0.12, i = 21.62 +/- 0.11, and z = 21.48 +/- 0.26 AB.
- The Liverpool Telescope observations note that some z-band exposures were discarded before stacking.
- No spectrum is reported in the provided circulars.
Redshift
What’s special vs typical