The sky is filled with comets, constellations, stars and many other celestial bodies. However, there is a constellation in the northern sky which is very small and is often overlooked. Though the stars that make up this constellation are dim, it consists of some of the finest objects in the sky that could be viewed through a telescope. The constellation is Canes Venatici. It is generally a Latin name for ‘hunting dogs’ and they are the dogs of the constellation Bootes the herdsman, with names Chara and Asterion. The constellation was charted/created by the Greek astronomer Ptolemy in the Ursa Major constellation as ‘informes’, meaning ‘unformed’. This constellation, after its creation was introduced in 1687 by Johannes Hevelius, another Polish astronomer. He introduced this constellation by creating a figure from the faint stars below the bear’s tail.
Some of the major stars that comprise the constellation include:
- Cor Caroli: It means ‘Charles’ heart’ and is the brightest star in the constellation. The star was named by a mathematician and physician to Charles I, Charles Scarborough in honour of Charles I. Its apparent magnitude varies between 2.84 to 2.98 and is approximately 110 light years distant from the earth.
- Chara: In Greek, it means ‘joy’ and is also known as Beta Canum Venaticorum. It is the second brightest star in Canes Venatici and appears to be similar in terms of age, mass and stage of evolution. Hence, it is referred to as the solar analogue or solar twin. A G–type main sequence dwarf, it is approximately 27.4 light years away from the earth and has a magnitude of about 4.26.
- La Superba: It is one of the reddest stars in the sky and is also known as Gamma Canum Venaticorum. An Italian astronomer Angelo Secchi from the 19th century named it La Superba due to its striking appearance. It is believed that the star was in the last stages of fusing its secondary fuel helium into carbon. A semi–regular variable star, it is the brightest J–star ever known. With a magnitude that varies between 4.8 and 6.3, it lies about 711 light years away from the earth.
- AM Canes Venaticorum: This star is classified as a cataclysmic variable star which irregularly increases dramatically in luminosity and later drops back to its quiescent state. They are typically binary stars composed of a white dwarf and a mass transferring secondary star. It has an apparent magnitude of about 14.18 and is approximately 2,000 light years distant.
RS Canum Venaticorum: It is another variable star which serves as a prototype for a class of variable stars. They are close binary stars that vary in luminosity. This period of variation is typically the orbital period of the solar system and fluctuates by 0.2 magnitudes.
Of the numerous deep sky objects, some of the notable ones are:
- M3 (Messier 3) or NGC 5272: It is one of the brightest or the larger globular clusters containing about 500,000 stars. With an estimated age of about 8 billion years, it was discovered by William Herschel in 1784. It has an apparent magnitude of about 6.2 and is approximately 33,900 light years distant from the earth.
- M51 or the Whirlpool nebula: It is a pair of spiral galaxies namely the NGC 5194 and NGC 5195. One of the best known galaxies in the night sky, it is connected by a tidal bridge full of interstellar dust. Its magnitude is 8.4 which is visible even with the binoculars and has a circular disk with a radius of 38,000 light years.
- The Sunflower Galaxy or M63: The second brightest galaxy after the Whirlpool Galaxy, it has a magnitude of about 9.3. It is approximately 37 million light years away from the earth.
The other notable stars are the SAB Galaxy or the M94, which appears like a comet; M106, another bright spiral galaxy; M51 group which includes numerous prominent galaxies; the Whale Galaxy, an edge–on spiral galaxy; NGC 5033, another spiral galaxy; NGC 5005, an inclined spiral galaxy; NG 4151, an intermediate spiral Seyfert galaxy; NGC 4168, a dwarf galaxy; NGC 5371, a galaxy seen face–on; NGC 4625, another dwarf galaxy; and Hockey Stick galaxies. It also has a meteor associated with it called as the Canes Venaticids.
Seen at latitudes between +90° and - 40°, Canes Venatici lies in the third quadrant of the northern hemisphere.
It occupies an area of about 465 square degrees, making it the 38th largest constellation in the sky. La Superba, one of its major stars is 711 light years from the earth and hence, it can be said that the distance of this constellation from the earth is 711 light-years.
As discussed earlier, the Bootes constellation has been represented with two dogs. Canes Venatici includes these two dogs of the Bootes. Peter Apian, German astronomer and Hevelius, Mayor of Danzing named the northern dog as Asterion, meaning ‘little star’ in Greek, and the southern star was named as ‘Chara’, meaning ‘joy’.
Canes Venatici is surrounded by constellations such as Bootes, Coma Berencies and Ursa Major.
