Iota Horologii

Iota Horologii

Dust disk around Iota Horologii.

Iota Horologii, also known as HR 810, is a Sun-like star with an exoplanet that moves in the most Earth-like orbit yet found. Iota Horologii has a surface temperature of 6150 K and a mass 1.25 times that of the Sun. It is believed to be about 625 million years old and is more metal-rich than the Sun by about 50%. It has drifted to its present position from the Hyades cluster where it formed.


Host star
Distance 50.5 light-years (15.5 pc)
Spectral type G0 V
Apparent magnitude 5.4


Mass (Jupiter=1) 2.26
Semi-major axis 0.93 AU (140 million km, 86 million miles)
Orbital period 320 days
Eccentricity 0.16
Discovery 1999, ESO Coudé Échelle Spectrometer, La Silla
Method of discovery radial velocity