05 July 2021
1. Cancer means ‘crab’ in Latin
2. It is one of the dimmest constellations in the Earth’s night sky
3. The Tropic of Cancer is named after this constellation
4. One of the star clusters it hosts has more than 1,000 stars
5. Two of its main stars, Asellus Borealis and Asellus Australis are known as the northern and southern donkey respectively
The constellation of Cancer makes up an upturned ‘Y’, and is often interpreted as depicting the top-view of a crab. The constellation consists of many stars and other deep-lying objects, most of which are relatively faint, resulting in Cancer being one of the dimmest constellations.
It is one of the 12 Greek Zodiac constellations, though the Chinese depict the very same constellation a bird rather than a crab. It is visible in both the Northern and Southern hemispheres, from late autumn to spring in the former and summer to autumn’s end in the latter.
In Greek mythology, Zeus had fathered a divine hero named Hercules, who was frequently tormented by his stepmother, Hera. She had made continuous attempts at killing Hercules, but to little avail.
Though he was not successfully murdered by Hera, the torment dished out by his stepmother soon drove Hercules insane. In a crazed frenzy, Hercules killed six of his own sons.
When he regained his senses, Hercules was overcome with remorse, and sought to serve penance by putting himself under King Eurystheus’ control. The King set Hercules a series of labors, with the second being to kill the ferocious Hydra, a multi-headed serpent that dwelled in the swamps surrounding Lake Lerna.
Hera thought this to be the time where her stepson would finally fall, but was unpleasantly shocked as Hercules began slaying the creature with relative ease. She then sent forth a crab to nip at his ankles, in hopes of distracting him, though Hercules simply crushed the crab under his foot before slaying the Hydra.
In honor of the crab’s service, Hera then placed it into the sky, birthing the constellation of Cancer.
The Constellation of Cancer is situated in the northern sky’s second quadrant, and is visible between latitudes -60 to +90 degrees. It is surrounded by the constellations of Leo, Hydra, Lynx, Gemini, Canis Minor, and Leo Minor, and is not an exceptionally small nor large constellation.
Of the 10 main stars it consists, there exists five celestial bodies of note: Altarf, the brightest star of Cancer; Acubens, which is also known as Alpha Cancri; Asellus Australis and Borealis, also known as Delta and Gamma Cancri; and Iota Cancri, a two-star system that lies 300 light years from Earth.