Iota Horologii

(The Planet Project)

Eri Iota Horologium is very similar to our own Sun, and has a Jupiter- like planet that orbits in just under a year.

THE PLANET

The left-hand circle shows the location of the class G (G0) dwarf star Iota Horologium, which is found in the deep southern end of the constellation to the east of Eridanus, Achernar, and another planet-holding star q1-Eridani. Iota Hor's planet, with a mass at least 1.94 times that of Jupiter, orbits with a period of 311.3 days, or 0.85 years at an average distance of 0.91 Astronomical Units (136 million kilometers, 84.6 million miles), not too much different from our own Earth. A modest orbital eccentricity of 0.24 takes the planet from as far as 1.12 AU from its parent star to 0.69 AU, from somewhat larger than the orbit of the Earth to about the distance of Venus from the Sun.

THE STAR

Iota Horologii is a fifth magnitude (near sixth, 5.41) near-solar clone, a class G0 dwarf star in deep southern Horologium not far from first magnitude Achernar. From a distance of 56 light years (near its planet-holding neighbor, q-1 Eridani), it shines with a luminosity 1.1 times that of the Sun, but with surface temperature of 5980 Kelvin, just 200 Kelvin warmer than solar. That combination gives a radius 20 percent greater than the Sun and a mass of about 1.1 times solar. Like most stars with planets, Iota Hor is metal-rich, with an iron abundance (relative to hydrogen) that may be as high as 80 percent greater than that found in the Sun.
Written by Jim Kaler. Return to The Planet Project or go to STARS.