Xi2 Canis Majoris

Xi2 Canis Majoris, which is Latinized from ξ2 Canis Majoris, is an astrometric binary star system in the southern constellation of Canis Major. With an apparent visual magnitude of +4.54, it is visible to the naked eye. Based upon an annual parallax shift of $26$, the system is approximately 390 light years distant from Earth. It is receding with a radial velocity of +26 km/s.

The binary nature of this system was determined based on changes in the proper motion of the visible component. Buscombe (1962) gave the white-hued primary a stellar classification of A0 V, indicating it is an A-type main-sequence star. However, Houk and Smith-Moore (1978) list it with a class of A0 III, which would match a more evolved giant star, also of the A-type. It is 339 million years old with a high rate of spin, having a projected rotational velocity of 145 km/s. The star is radiating 224 times the Sun's luminosity from its photosphere at an effective temperature of 8,799 K.