This is the system the Castor star is in.
http://www.absoluteastronomy.com/topics/Castor_(star)
Parameter
Star Component
Aa
Ab
Ba
Bb
Ca
Cb
Spectral type
Stellar classification
In astronomy, stellar classification is a classification of stars based on its spectral characteristics. The spectral class of a star, is a designation of a class to a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective...
A1 V
Unknown (probably M5 V)
A2 Vm
M2 V
M0.5 Ve
M0.5 Ve
Mass (M☉
Solar mass
The solar mass , , is a standard way to express mass in astronomy, used to describe the masses of other stars and galaxies. It is equal to the mass of the Sun, about two nonillion kilograms or about 332,950 times the mass of the Earth or 1,048 times the mass of Jupiter.The solar mass can be...)
2.15
0.4–0.6
1.7
0.4–0.6
0.62
0.57
Radius (R☉
Solar radius
In astronomy, the solar radius is a unit of length used to express the size of stars. It is equal to the current radius of the Sun. Its value is: ....)
2.3
?
1.6
?
0.76
0.68