Pegasus

The myth

Pegasus is the winged horse that sprang from the blood of Medusa when Perseus cut off her head. Only the front half of the horse is drawn in the stars, and upside down, as though it is flying up out of the sky rather than across it. In another story the hero Bellerophon tamed Pegasus with a golden bridle and rode him to kill the monster Chimera, then fell trying to ride him up to Olympus.

How to find it

Look for the Great Square of Pegasus, four stars marking out a large, nearly empty box high in the autumn sky. It is bigger than most people expect, and the giveaway is that there is almost nothing inside it. One corner of the square is actually shared with Andromeda next door, which is how the two connect. From the northern hemisphere the square is a signpost of autumn evenings, rising in the east as summer ends.

A signpost for the autumn sky

The square works like a map. The two stars on its western side point south toward Fomalhaut, the lonely bright star of the southern fish. Just below its southern edge sits the faint Circlet of Pisces. And the corner star Alpheratz leads off northeast into the chain of Andromeda and on to Perseus. Once you know the square, the whole autumn sky falls into place.

Stars you can find in your chart

Pegasus sits north of the Sun’s path, but its stars fall at zodiac degrees close to the March equinox. By Hali’s 2026 star positions Algenib, at the bottom corner of the square, is at 9 degrees of the sign Aries, Markab at 23 degrees of Pisces and Scheat at 29 degrees of Pisces, the very last degree of the zodiac. The Sun passes Markab around 14 March and Scheat around 20 March. Ptolemy gave the bright stars of the horse the nature of Mars and Mercury.

A planet around another sun

In 1995 the star 51 Pegasi, a faint Sun-like star near the square, became the first ordinary star found to have a planet orbiting it. The discovery won a Nobel Prize and started the search that has since found thousands of planets around other stars.

Common confusions

The Great Square is not a constellation of its own. Three of its stars belong to Pegasus and one, Alpheratz, to Andromeda. Pegasus is also not a zodiac constellation, though its stars sit at zodiac degrees by longitude, which is how fixed star astrologers use them.