HD 216770
Template:Short description Template:Starbox begin Template:Starbox observe Template:Starbox character Template:Starbox astrometry Template:Starbox detail Template:Starbox catalog Template:Starbox reference Template:Starbox end
HD 216770 is a star with an orbiting exoplanet in the southern constellation of Piscis Austrinus. With an apparent visual magnitude of 8.11,<ref name="Mayor2004"/> it is too faint to be visible to the naked eye. It is located at a distance of 120 light years from the Sun, as determined by parallax measurements, and is drifting further away with a radial velocity of 31.1 km/s.<ref name=GaiaRV/> The star shows a high proper motion, traversing the celestial sphere at an angular rate of Template:Val.<ref name=Luyten1995/>
The spectrum of HD 216770 presents as a late G-type main-sequence star, a yellow dwarf, with a stellar classification of G9VCN+1,<ref name=Gray_et_al_2006/> where the suffix notation indicates anomalously strong band of CN. The star is smaller than the Sun, with 74% of the Sun's mass and 93% of the Sun's radius.<ref name=Stassun/> It is about three billion years old and is spinning slowly with a rotation period of 35.6 days.<ref name="Mayor2004"/> The abundance of iron, a measure of the metallicity of the star, is higher than solar. The star is radiating 79% of the luminosity of the Sun from its photosphere at an effective temperature of 5,399 K.<ref name=Stassun/>
In 2003 an exoplanet was announced orbiting it by the Geneva Extrasolar Planet Search team.<ref name="Mayor2004"/> As the inclination of the orbital plane is unknown, only a lower bound on the mass of the object can be determined. It has at least 65% of the mass of Jupiter. The body has an eccentric orbit with a period of 118.5 days.
Template:OrbitboxPlanet begin Template:OrbitboxPlanet Template:Orbitbox end