About

Canes Venatici ( KAY-neez vin-AT-iss-eye) is one of the 88 constellations designated by the International Astronomical Union (IAU). It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for 'hunting dogs', and the constellation is often depicted in illustrations as representing the dogs of Boötes the Herdsman, a neighboring constellation. Cor Caroli is the constellation's brightest star, with an apparent magnitude of 2.9. La Superba (Y CVn) is one of the reddest naked-eye stars and one of the brightest carbon stars. The Whirlpool Galaxy is a spiral galaxy tilted face-on to observers on Earth, and was the first galaxy whose spiral nature was discerned. In addition, quasar TON 618 is one of the most massive black holes with the mass of 66 billion solar masses.

History and mythology

The stars of Canes Venatici are not bright. In classical times, they were listed by Ptolemy as unfigured stars below the constellation Ursa Major in his star catalogue. In medieval times, the identification of these stars with the dogs of Boötes arose through a mistranslation: some of Boötes's stars were traditionally described as representing the club (Greek: κολλοροβος, kollorobos) of Boötes. When the Greek astronomer Ptolemy's Almagest was translated from Greek to Arabic, the translator Hunayn ibn Ishaq did not know the Greek word and rendered it as a similar-sounding compound Arabic word for a kind of weapon, writing العصا ذات الكُلاب al-'aşā dhāt al-kullāb, which means 'the staff having a hook'. When the Arabic text was later translated into Latin, the translator, Gerard of Cremona, mistook كُلاب kullāb ('hook') for كِلاب kilāb ('dogs'). Both written words look the same in Arabic text without diacritics, leading Gerard to write it as Hastile habens canes ('spearshaft-having dogs'). In 1533, the German astronomer Peter Apian depicted Boötes as having two dogs with him. These spurious dogs floated about the astronomical literature until Hevelius decided to make them a separate constellation in 1687. Hevelius chose the name Asterion for the northern dog and Chara for the southern dog, as Canes Venatici, 'the hunting dogs', in his star atlas. In his star catalogue, the Czech astronomer Antonín Bečvář assigned the names Asterion to β CVn and Chara to α CVn. Although the International Astronomical Union dropped several constellations in 1930 that were medieval and Renaissance innovations, Canes Venatici survived to become one of the 88 IAU designated constellations.