Pegasus
The great square of the autumn sky
Best on September–November evenings · northern sky.
Pegasus is the winged horse of Greek myth and the defining constellation of the autumn sky. Its most famous feature is the Great Square — a large, nearly perfect quadrilateral of four bright stars that dominates the southern sky on autumn evenings from the northern hemisphere. Once you know the Great Square, you have a landmark to navigate the whole autumn sky.
How to find it
On autumn evenings, face south from the northern hemisphere and look high for a large, nearly perfect square of four bright stars with surprisingly little else inside it — that emptiness is part of what makes it easy to spot. A good starting point is the Andromeda constellation: trace two chains of stars leading away from the Square's corner star, and you've walked right into Pegasus's neighbor. Alternatively, follow the two outer stars of Cassiopeia's W downward toward the south and you'll land close to the Square.
Brightest stars
Orange-tinted Enif marks the horse's nose at magnitude 2.39, though it sits off on its own well away from the Square. The Square's own corners are defined by Scheat (magnitude 2.42), Markab (2.49), and Algenib (2.83), with the fourth corner technically belonging to Andromeda.
Worth seeing
The Great Square itself is the showpiece — a vast, nearly empty box of sky that makes a surprisingly useful dark-sky test: the more faint stars you can count inside it on a clear night, the better your skies really are.
Frequently asked
When is Pegasus visible?
Pegasus is best seen on autumn evenings, roughly September through November, when it climbs high in the southern sky for northern hemisphere observers. From southern latitudes it's visible but sits lower on the horizon.
What are the brightest stars in Pegasus?
Enif (magnitude 2.39) is the brightest, an orange star marking the horse's nose. The Great Square is outlined by Scheat (2.42), Markab (2.49), and Algenib (2.83), with Matar (2.94) and Homam (3.4) filling out the body.
Which hemisphere is Pegasus best seen from?
The northern hemisphere, where it passes high overhead on autumn evenings. Southern hemisphere observers can see it too, but it stays relatively low above the northern horizon.
Nearby constellations
Pisces · Aquarius · Delphinus · Andromeda · Cygnus · Capricornus · Cepheus · Cassiopeia