Constellation: Cancer

Cancer

Cancer (20 July-10 August)

Cancer is one of the twelve constellations of the zodiac. Its name is Latin for crab and it is commonly represented as one. ... Cancer is a medium-size constellation with an area of 506 square degrees and its stars are rather faint, its brightest star Beta Cancri having an apparent magnitude of 3.5.

Cancer constellation is located in the northern sky. Its name means “the crab” in Latin.

Cancer is the faintest of the 12 zodiac constellations. Its symbol is . The constellation was first catalogued by the Greek astronomer Ptolemy in the 2nd century.

Cancer contains a number of famous deep sky objects, among them the open cluster Praesepe, also known as the Beehive Cluster (Messier 44), the open cluster Messier 67, and the interacting spiral galaxies NGC 2535 and NGC 2536.

MYTH

n mythology, Cancer is associated with the crab in the story of the Twelve Labours of Heracles (represented by the Hercules constellation). In the myth, Hera sends the crab to distract Hercules while the hero is fighting the Lernaean Hydra, the serpent-like beast with many heads and poisonous breath, represented by Hydra constellation. When the crab tries to kill Hercules, Hercules kicks it all the way to the stars.

In another version, the crab gets crushed instead and Hera, a sworn enemy of Hercules, places it in the sky for its efforts. However, she places the crab in a region of the sky that has no bright stars, because despite its efforts, the crab was not successful in accomplishing the task. Cancer does not have any stars brighter than fourth magnitude.

History

Cancer is said to have been the place for the Akkadian Sun of the South, perhaps from its position at the summer solstice in very remote antiquity. But afterwards it was associated with the fourth month Duzu (June–July in the modern western calendar), and was known as the Northern Gate of Sun.[citation needed]

Showing but few stars, and its brightest stars being of only 4th magnitude, Cancer was often considered the "Dark Sign", quaintly described as black and without eyes. Dante, alluding to this faintness and position of heavens, wrote in Paradiso:

“

Then a light among them brightened, So that, if Cancer one such crystal had, Winter would have a month of one sole day.

”

Cancer was the location of the Sun's most northerly position in the sky (the summer solstice) in ancient times, though this position now occurs in Taurus due to the precession of the equinoxes, around June 21. This is also the time that the Sun is directly overhead at 23.5°N, a parallel now known as the Tropic of Cancer.[1]

In Greek mythology, Cancer is identified with the crab that appeared while Hercules was fighting the many-headed Hydra. The crab bit Hercules on the foot, Hercules crushed it and then the goddess Hera, a sworn enemy of Hercules, placed the crab among the stars.

FACTS, LOCATION & MAP

Cancer is the 31st largest constellation in the sky, occupying an area of 506 square degrees. It lies in the second quadrant of the northern hemisphere (NQ2) and can be seen at latitudes between +90° and -60°. The neighboring constellations are Canis Minor, Gemini, Hydra, Leo, Leo Minor, and Lynx.

Cancer belongs to the Zodiac family of constellations, along with Aries, Taurus, Gemini, Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius, and Pisces.

Cancer contains two Messier objects – the Beehive Cluster (M44, NGC 2632) and M67 (NGC 2682) – and has two stars with known planets. The brightest star in the constellation is Al Tarf, Beta Cancri. The Delta Cancrids are the only meteor shower associated with the constellation.

Cancer Constellation Map, by IAU and Sky&Telescope magazine

References:

https://en.wikipedia.org/wiki/Cancer_(constellation) http://www.constellation-guide.com/constellation-list/cancer-constellation/