One story, six constellations
Most constellations are loners. The "Royal Family" is different: six neighbouring autumn constellations that act out a connected myth. Trace the gold shapes below, then follow the dashed lines to read the plot.
How the story runs across the sky
It starts with vanity. Cassiopeia, queen of Aethiopia, boasts that she and her daughter are more beautiful than the Nereids, the sea nymphs. Poseidon answers the insult by sending Cetus, a sea monster, to ravage the coast. An oracle tells King Cepheus that the only way to appease the god is to chain his daughter Andromeda to a rock at the water's edge as a sacrifice.
Enter Perseus, flying home from killing the Gorgon Medusa, whose severed head still turns onlookers to stone. From the blood of Medusa the winged horse Pegasus had already sprung. Perseus spots Andromeda, kills Cetus, frees her, and marries her. Six constellations, one rescue. The gods set them all in the northern autumn sky, where Cassiopeia circles the pole upside-down as a lasting rebuke for her pride.
On October and November evenings, look high in the north and east. Cassiopeia's W, the Great Square of Pegasus, and the chain of Andromeda are all up together. Once you see them as one family, the autumn sky reads like a page.
Meet the Royal Family
Cassiopeia
The vain queen whose boast started it all, frozen as a W that wheels around the pole. Home to the supernova remnant Cassiopeia A.
Cepheus
The king, drawn as a house beside his wife. Holds the Garnet Star and Delta Cephei, the star that gave us the cosmic distance ladder.
Andromeda
The chained princess, and the constellation that carries the nearest large galaxy to our own, 2.5 million light-years away.
Perseus
The hero, holding the demon star Algol, Medusa's winking eye. Source of the August Perseid meteor shower.
Pegasus
The winged horse and its Great Square. Home to 51 Pegasi, the first sun-like star found with a planet, and to Stephan's Quintet.
Cetus
The sea monster, sprawling and dim. Holds Mira, the first variable star ever found, and the nearby sun-like star Tau Ceti.
More myths written in the stars
The dragon, the harp, the eagle, and the swan all carry their own stories, and several already have full pages on this site.
Draco
Ladon, the hundred-headed dragon that guarded the golden apples, slain by Heracles and coiled around the pole.
Lyra
The lyre of Orpheus, whose music charmed the underworld itself. Anchored by brilliant Vega.
Cygnus
The swan and the Northern Cross, marked by the supergiant Deneb. It holds the first black hole ever found.
Aquila
The eagle that bore Zeus's thunderbolts, led by Altair, the cowherd of the Tanabata legend.
Hercules
The kneeling strongman of the twelve labours, home to the great clusters M13 and M92.
Orion
The great hunter, fixed forever across the sky from Scorpius, the scorpion that killed him.
Ursa Major
The Great Bear, Callisto turned into a bear, carrying the Big Dipper and the galaxies M81 and M82.
Boötes
The Herdsman who drives the bears around the pole, anchored by brilliant Arcturus, the bear-guardian.
Greece was not the only voice
These star patterns belong to everyone, and most cultures read their own figures into them. The stars of the Pleiades gather their own myths from Greece to Japan to Aboriginal Australia. Vega and Altair are a weaver and a cowherd in the East Asian Tanabata legend, kept apart by the river of the Milky Way. Algol, the demon's head in the Greek and Arabic traditions, was logged by Chinese astronomers as Tseih She, "the piled-up corpses." The Greek names stuck to our charts through history, but they sit on top of a much older, much wider human habit of telling stories to the stars.
The Greeks turned a night sky into a theatre, and left the house lights on for three thousand years. We still look up into the same play, learning the science of the actors while the old story keeps running overhead.
All Astronomy Notes · Cassiopeia · Cepheus · Andromeda · Perseus · Pegasus · Cetus · Draco · Lyra