Perseus: The Monster Slayer

Late autumn is the best time to view the constellation Perseus. Learn more!

by Jaime McLeod Updated: January 16, 2024

Perseus was one of the original 48 constellations cataloged by the Second Century Greek astronomer Ptolemy, and is still one of 88 officially recognized modern constellations. It sits on the south side of the sky in the Northern Hemisphere, near Aries, Taurus, Auriga, Camelopardalis, Cassiopeia, Andromeda, and Triangulum.

In all, Perseus contains 65 stars, 22 of which make up its shape, said to be the mythological Greek hero Perseus, an armored warrior brandishing a sword in one hand and the head of the slain snake-haired monster Medusa in the other. One of the most famous stars in Perseus is Algol, a variable star that appears to grow dimmer for a few hours every three days or so, then brightens again. Called the “winking demon star,” Algol’s name means “the ghoul” in Arabic. The ancient Greeks said it was the eye of Medusa.

Other notable stars include the constellation’s brightest, Mirfak, which is 42 times larger than our own Sun, and Nova Persei 1901, a bright nova, or exploding star, discovered in 1901.

Perseus also contains a number of deep sky objects, including two Messier objects, the open cluster M34 and the planetary nebula M76. It also contains the Alpha Persei Cluster, the so-called Double Cluster (NGC 869 and NGC 884), the California Nebula (NGC 1499), and the nebula NGC 1333, NGC 1260, which contains the supernova SN 2006gy, the second brightest known object in the universe. Finally, Perseus is home to a giant molecular cloud.

In Greek mythology, Perseus was among the most celebrated heroes. He was the child of the god Zeus and a mortal woman named DanaÃ«, daughter of King Acrisius of Argos. Acrissus had been warned by an oracle that, one day, he would be killed by his daughter’s son. To prevent the prophecy from coming to pass, Acrisius locked his daughter up in a high tower. This proved to be no obstacle for Zeus, however, who came to DanaÃ« as a golden mist. Once their child, Perseus, was born, Acrisius had both his daughter and the boy locked in a trunk and cast into the sea. DanaÃ« prayed to the gods to protect them, though, and the trunk washed up safely on the shores a small island called Seriphos. DanaÃ« and Perseus were found by a kindly fisherman named Dictys, who took them home and raised the boy as his own.

Perseus’s life of adventure started after he was tricked by a treacherous step-uncle, Polydectes, into promising to bring home the head of the snake-haired monster Medusa, whose gaze turned anyone it fell upon to stone. Polydectes, who wanted to get the boy out of the way so he could steal DanaÃ« from his brother, did not believe the Perseus would return from such a dangerous task. With great cunning, and a little help from the goddess Athena, though, Perseus eventually came to possess the special weapons needed for the task, including a mirrored shield that would reflect Medusa’s gaze back at herself, and a special knapsack that could safely hold his gruesome trophy. With these tools, he was able to overcome Medusa’s deadly glance and take her head.

On his way home to make good on his promise, Perseus encountered a beautiful girl chained to a stone. She was about to be devoured by a sea serpent. This was Andromeda, daughter of the queen Cassiopeia, who was taken from her parents by the god Poseidon as a punishment for the queen’s vanity. Perseus slew the monster and saved the girl, but when he tried to claim her hand in marriage, he was confronted by her previous suitor. Soon, a great battle was underway for the hand of Andromeda. Perseus, outnumbered, finally bested his opponent by pulling out the head of Medusa and turning him to stone.

Eventually, Perseus found himself back in Argos, where he accidentally killed his grandfather, who he did not know, while competing in the discus throw. As the next rightful her to the throne, Perseus then became king of Agros, where he ruled for many years.

Jaime McLeod

Jaime McLeod is a longtime journalist who has written for a wide variety of newspapers, magazines, and websites, including MTV.com. She enjoys the outdoors, growing and eating organic food, and is interested in all aspects of natural wellness.