Chara, or Beta Canum Venaticorum, is the fainter of the two of stars that dominate the modern constellation of Canes Venatici, the Hunting Dogs. The dogs are held by Bootes as he pursues Ursa Major around the pole; the constellation was invented by Hevelius in the mid-1600s.
"Chara", a lovely name for a star that vaults across the heavens during the northern spring, comes from Greek, meaning "joy." Chara and Cor Caroli (α CVn) make up the "southern dog," while the "northern dog" is represented by a small group of stars to the northeast of Cor Caroli. Chara was originally the name for the southern dog itself; the northern one was called "Asterion" for "Little Star." But eventually Chara got the name to itself.
Properties
Chara's most interesting aspect is its similarity to the Sun. Most stars are members of multiple star systems. But Chara, like the Sun, seems to be single. At a distance of 27 light years, Chara provides a good chance to see what the Sun would look like at stellar distances. It is a warm class G star with a temperature of 5860 K, a mass only 4% smaller, and a radius 4% larger. It is 25% more luminous than our Sun; since main-sequence hydrogen-fusing stars brighten and swell somewhat as they age, Chara may be one or two billion years older than the Sun.
Chara is also detectable in the X-ray part of the spectrum, implying that like our Sun, it is also surrounded by a hot corona. Chara even rotates at a similar speed. Its biggest difference, other than luminosity, seems to be its metal content, only about 60% as much iron as the sun.
Could Chara have planets too? Chara may have a spectroscopic companion that orbits every 6.65 years, at a distance around 3 AU. If it does exist, our Sun would look almost the same from them as Chara does to us.
[Adapted from STARS by Jim Kaler, Professor Emeritus of Astronomy, University of Illinois]