Star Lore Of All Ages/Canes Venatici
Canes Venatici
The Hunting Dogs
The Hunting dogs
The asterism Canes Venatici, or the Hunting Dogs, is so closely associated with Boötes that a description of it comes properly in this place.
This star group is a modern one, having been formed by Hevelius in 1690. These stars are supposed to represent two hunting dogs or hounds, which, held in leash by the Bear Driver, pursue the Great Bear as it circles the Pole. The northern dog is named "Asterion," the southern "Chara." In the neck of the latter is situated the lucida of the asterism, a third magnitude star which bears the name of "Cor Caroli," or "Charles's Heart." It was named by Sir Charles Scarborough in memory of Charles I., not Charles II., as often appears. Although it is said Charles II. deserved the honour, as he had the good sense to found Greenwich Observatory. Allen states that this star was set apart in 1725 by Halley, when Astronomer Royal, as the distinct figure Cor Caroli. In China this star was known as "Chang Chen," "a seat," and three stars near the head of Asterion they called "the Three Honorary Guardians of the Heir Apparent." It is a wide double and is easily seen in a small telescope, hence it is a favourite object with amateur astronomers.
Cor Caroli is one of the four stars forming the famous figure known as "the diamond of Virgo," and comes to the meridian at 9 p.m. on the 20th of May.
About seven degrees north and two degrees west of Cor Caroli is the 5.5 magnitude red star which Father Secchi called "La Superba," because of "the superbly flashing brilliancy of its prismatic rays."
The great Spiral Nebula of Lord Rosse, sometimes called "the Whirlpool Nebula," can be seen in this region with a low power about three degrees south-west of η Ursæ Majoris.