Procyon

Procyon is the brightest star in Canis Minor and the eighth brightest in the night sky at magnitude 0.38. It is a yellow-white subgiant/main-sequence star of spectral type F5IV-V, located only 11.5 light-years from Earth. Procyon is 1.5 times the mass of the Sun and about 7 times more luminous. Like Sirius, it has a white dwarf companion: Procyon B, discovered in 1896, orbits with a period of about 41 years. The white dwarf has about 0.6 solar masses packed into a body the size of Earth.

Procyon is easy to locate as part of the Winter Triangle, along with Sirius and Betelgeuse. Its pale yellow-white color contrasts nicely with the blue-white of Sirius. The white dwarf companion Procyon B (magnitude 10.7) is even more challenging to observe than Sirius B, as it lies very close to the primary — typically only 4-5 arcseconds away. Resolving it requires an excellent telescope of at least 300mm and superb seeing conditions. Best observed from January through April.

The name Procyon comes from the Greek 'Prokyon' meaning 'before the dog,' because it rises shortly before the Dog Star Sirius when observed from most northern latitudes. Friedrich Bessel predicted the existence of the white dwarf companion in 1844, but it wasn't visually confirmed until John Martin Schaeberle observed it in 1896 using the Lick Observatory 36-inch refractor.