About

Pegasus is a constellation in the northern sky, named after the winged horse Pegasus in Greek mythology. It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and is one of the 88 constellations recognised today. With an apparent magnitude varying between 2.37 and 2.45, the brightest star in Pegasus is the orange supergiant Epsilon Pegasi, also known as Enif, which marks the horse's muzzle. Alpha (Markab), Beta (Scheat), and Gamma (Algenib), together with Alpha Andromedae (Alpheratz) form the large asterism known as the Square of Pegasus. Twelve star systems have been found to have exoplanets. 51 Pegasi was the first Sun-like star discovered to have an exoplanet companion.

History and mythology

The Babylonian constellation IKU (field) had four stars of which three were later part of the Greek constellation Hippos (Pegasus). Pegasus, in Greek mythology, was a winged horse with magical powers. One myth regarding his powers says that his hooves dug out a spring, Hippocrene, which blessed those who drank its water with the ability to write poetry. Pegasus was born when Perseus cut off the head of Medusa, who was impregnated by the god Poseidon. He was born with Chrysaor from Medusa's blood. Eventually, it became the horse for Bellerophon, who was asked to kill the Chimera and succeeded with the help of Athena and Pegasus. Despite this success, after the death of his children, Bellerophon asked Pegasus to take him to Mount Olympus. Though Pegasus agreed, he plummeted back to Earth after Zeus either threw a thunderbolt at him or sent a gadfly to make Pegasus buck him off. In mediaeval Persia, Pegasus was depicted by al-Sufi as a complete horse facing east, unlike most other uranographers, who had depicted Pegasus as half of a horse, rising out of the ocean. In al-Sufi's depiction, Pegasus's head is made up of the stars of Lacerta the lizard. Its right foreleg is represented by β Peg and its left foreleg is represented by η Peg, μ Peg, and λ Peg; its hind legs are marked by 9 Peg. The back is represented by π Peg and μ Cyg, and the belly is represented by ι Peg and κ Peg. In Chinese astronomy, the modern constellation of Pegasus lies in The Black Tortoise of the north (北方玄武), where the stars were classified in several separate asterisms of stars. Epsilon and Theta Pegasi are joined with Alpha Aquarii to form Wei 危 "rooftop", with Theta forming the roof apex. In Hindu astronomy, Pegasus is contained within the 25th nakshatra lunar mansion Purva Bhadrapada. More specifically, it represented a bedstead that was a resting place for the Moon. For the Warrau and Arawak peoples in Guyana the stars in the Great Square, corresponding to parts of Pegasus and of Andromeda, represented a barbecue, taken up to the sky by the seven hunters of the myth of Siritjo.