HD 72659

HD 72659 is a star in the equatorial constellation of Hydra. With an apparent visual magnitude of 7.46, its yellow-hued star is too faint to be viewed with the naked eye. Parallax measurements provide a distance estimate of 169.4 light years from the Sun, and it has an absolute magnitude of 3.98. The star is drifting closer with a radial velocity of −18.2 km/s.
This is a Sun-like main sequence star with a stellar classification of G2V, indicating that it is generating energy through core hydrogen fusion. It is older than the Sun with an age of about seven billion years, and is spinning with a projected rotational velocity of 5.1 km/s. The star has 7% greater mass than the Sun and a 38% larger radius. It is radiating more than double the Sun's luminosity from its photosphere at an effective temperature of 5,956 K. The metallicity of the stellar atmosphere is similar to the Sun.

Planetary system

An extrasolar planet was discovered orbiting this star in 2003 via the Doppler method. This is a superjovian planet with an eccentric orbit, completing a lap around its host star every. In 2022, the inclination and true mass of HD 72659 b were measured via astrometry, along with the detection of a second substellar companion, likely a brown dwarf. The orbit of the brown dwarf lies in the so-called brown dwarf desert, regions with a deficit of brown dwarfs. The host star is very old and thus HD 72659 b and c can not be directly imaged, even with the most modern equipment such as the James Webb Space Telescope. The moderate eccentricity of planet b may be the result of Kozai-Lidov oscillations.