HD 102365
HR 4523 (66 G. Centauri) is a binary star system that is located in the northeastern part of the Centaurus constellation, at a distance of about 30.07 ly (9.22 pc) from the Solar System. The larger member of the system is a G-type star that is smaller than the Sun but of similar mass. It has a common proper motion companion that was discovered by W. J. Luyten in 1960. This M-type star appears to be in a wide orbit around the primary at a current separation of about 211 astronomical units (AU), (or 211 times the separation of the Earth from the Sun). By comparison, Neptune orbits at an average distance of 30 AU.
The stellar classification for the primary star in this system is G2V; the same as the Sun. That of the red dwarf companion is M4V. The primary star has an estimated 86% to 89% the mass of the Sun, 96% of the Sun's radius, and 85% of the Sun's luminosity. It is a slow rotator, with a projected rotational velocity of 0.5 km/s. Age estimates range from 4.5–5.7 billion years (Gyr) up to 7.1 Gyr or 9.48 Gyr. Compared to the Sun, it only has about 52% of the abundance of elements other than hydrogen and helium; what astronomers term the metallicity of a star.
