Binary star in the constellation Canes Venatici
consisting of a brighter component (A) of
visual magnitude 2.9 and a companion (B) of
magnitude 5.5. It is the prototype for a group of
unusual spectrum-variable stars that show strong
and fluctuating absorption lines of silicon,
chromium,strontium, or certain rare earths.
[A] Cor Caroli (Alpha-2) is a "magnetic star," and
possesses one of the strongest known
magnetic fields.
No change in the relative position of the stars has
been observed since 1830. This indicates that the
orbital period of the pair must be very long.