Procyon is also known as Alpha Canis Minoris, HD 61421, and HR 2943. Nearby Bright star system. Nearest yellow white star (F5 IV–V) to the Sun and the closest star to Sirius. It is the 7th brightest star in the sky. Has a white dwarf companion B. Has about 50% more mass than the Sun and about twice its radius. It is a BY-Draconis type of variable (unusual for a bright star) and entering the last stage of its life on the main sequence, heading towards a sub-giant, as its core seems to have exhausted its supply of Hydrogen and is starting to fuse Helium. Its habitable zone, which is 2 to 4 AU, may be disrupted by B, which is only 9 to 21 AU away. Star B was first predicted due to its effect on A's proper motion in 1844 and later spotted in 1896. It was probably about the same mass as Star A, and sterilized the system when it went into a giant phase. Luyten's Star is only 1.2 light years away, near enough to stir up any Oort clouds in either system and would be dimly visible.