HD 121504 is a star with an orbiting exoplanet in the southern constellation of Centaurus. It is located at a distance of 136 light years from the Sun based on parallax measurements, and is drifting further away with a radial velocity of 19.6 km/s. With an apparent visual magnitude of 7.54, this star is too faint to be visible to the naked eye. It shows a high proper motion, traversing the celestial sphere at an angular rate of .
The spectrum of this star presents as an ordinary G-type main-sequence star, a yellow dwarf similar in appearance to the Sun, having a stellar classification of G2V. It is roughly two billion years old and is spinning with a rotation period of 8.6 days. The star has 16% more mass than the Sun and a 15% greater radius. The metallicity (the abundance of elements more massive than helium) is higher than solar. The star is radiating 162% of the luminosity of the Sun from its photosphere at an effective temperature of 6,089 K.
A nearby visual companion, designated as SAO 241323 has been proposed as a component of the system. However, the pair form an optical binary with an angular separation of, and in reality this is a white giant star located thousands of light years away.
In 2000 the Geneva Extrasolar Planet Search Team announced the discovery of an extrasolar planet orbiting the star.[1]