Beta Canum Venaticorum - Observations

Observations

At apparent magnitude 4.26, Beta Canum Venaticorum is the second brightest star in the constellation. It has a stellar classification of G0 V, and so is a G-type main sequence star. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. The spectrum of this star shows a very weak emission line of singly ionized calcium (Ca II) from the chromosphere, making it a useful reference star for a reference spectrum to compare with other stars in a similar spectral category. (The Ca-II emission lines are readily accessible and can be used to measure the level of activity in a star's chromosphere.)

β CVn is considered to be slightly metal-poor, which means it has a somewhat lower portion of elements heavier than helium when compared to the Sun. In terms of mass, age and evolutionary status, however, this star is very similar to the Sun. As a result it has been called a solar analog. It is about 3% more massive than the Sun, with a radius 12% larger than the Sun's and 15% greater luminosity.

The components of this star's space velocity are (U, V, W) = (–25, 0, +2) km/s. In the past it was suggested that it may be a spectroscopic binary. However, further analysis of the data does not seem to bear that out. In addition, a search for a brown dwarf in orbit around this star failed to discover any such companion, at least down to the sensitivity limit of the instrument used.