Perseus Constellation Facts
perseus constellation
Perseus is easily visible in the night sky due to the brightness of its stars.
  • Perseus is visible from August to March in the Northern hemisphere.
  • It is visible in northerly areas of the Southern hemisphere from mid spring to early summer.
  • Perseus is relatively bright and can be at least partially viewed even in well lit areas.
  • The annual Perseids meteor shower emanates from the direction of the constellation.
  • The Perseids occur from mid July to mid August, at times one meteor can be seen every minute.
  • The shower happens as a result of Earth passing through a trail of debris left by the comet Swift-Tuttle.
  • The Little Dumbbell and California nebulae are located within the Perseus constellation.
  • Perseus is near several constellations whose names derive from the adventures of the Greek hero, known as the Perseus Group.
  • Other constellations in the Perseus Group include Andromeda, Cassiopeia and Pegasus.
  • Perseus has been recognized as a constellation for at least 2,000 years.

Perseus Mythology

perseus mythology
The Greek mythological hero Perseus holding the head of the gorgon Medusa.
Perseus was a Greek mythological hero whose adventures provide the background stories of other constellations. He was fathered by the King of Gods Zeus who seduced his mother Danae, a beautiful princess whose father was the King of Argos.
The King of Argos previously consulted an Oracle who predicted that his daughter’s son would eventually kill him. After Perseus was born the King therefore placed his daughter and newly born grandson into a wooden chest and sent them adrift into the sea. The pair survived and landed safely on an island, there they were taken in by a local nobleman who raised the young hero through his childhood. Once Perseus had reached adulthood the nobleman sent him on his most famous adventure, to slay Medusa, a snake haired Gorgon whose gaze could turn a man to stone. Perseus managed to cut off the monster’s head, avoiding her gaze with the aid of mirrors. Perseus did eventually kill the King of Argos, striking him accidently in the head with a javelin at an athletic competition.

Main Stars in the Perseus Constellation
perseus constellation
The number next to each star is its apparent magnitude, its brightness from our point of view on Earth, the lower the number the brighter the star in the night sky.
With no traditional name the star is simply known as Gamma Persei, it's actually a binary system located around 240 light years from Earth, the primary star eclipses the other every 15 years causing it to appear dimmer in the night sky for a couple of weeks.
Also known as Alpha Persei, Mirfak is located around 500 light years from Earth and is the brightest star in the constellation, it's a white supergiant with a diameter around 30 times larger than the sun.
Also known as Beta Persei, Algol is actually a three star system located around 90 light years from Earth, the primary star is eclipsed by one of its less bright companions every 3 days causing its brightness to dip considerably for several hours. In the late 18th century the star was the first such eclipsing binary to be discovered. Historically Algol has been referred to as the "Demon Star", this may be due to the ancients perceiving its dimming in brightness as a harbinger of bad luck.
Gorgonea Tertia
Also known as Rho Persei, Gorgonea Tertia is a red giant around 300 light years from Earth, it is 150 times larger in diameter than the sun.
Epsilon Persei is a binary or possible triple star system 640 light years from Earth, the primary star has surface temperatures 5 times hotter than the sun with a mass around 14 times greater.
Zeta Persei is a blue supergiant around 750 light years from Earth, it is more than 25 times larger in diameter than the sun and almost 50,000 times as luminous.

Note: Although it may look like east and west are the wrong way wrong round on star charts they are actuallly designed to be used as if they are being held above the head.
Finding Perseus - Northern Hemisphere
finding perseus northern hemisphere
The chart shows the position of Perseus over most of the United States in January at 8pm. This chart can also be applied to other areas of the Northern hemisphere such as Canada, the UK and Europe.

In August and September the constellation will first appear low on the north-eastern horizon around 11pm, gradually moving higher in the sky before appearing directly overhead before day break.

In October and November Perseus will be visible low on the horizon in the north-east around 8pm, by 3am the constellation will be directly overhead before moving towards the north-western horizon.

In December and January it will be visible in the eastern night sky at around 6pm, moving higher in the sky eventually reaching directly overhead at around 10pm, then reaching the north-western horizon before day break.

In February and March the constellation will first appear overhead around 7pm, moving towards the north-western horizon as the night moves on.

Finding Perseus - Southern Hemisphere
finding perseus southern hemisphere
The chart shows the position of Perseus over Northern Australia in December at 11pm. This chart can also be applied to more northerly areas of the Southern hemisphere. In Southern Australia and other southerly regions of the hemisphere Perseus is not visible.
In November the constellation will appear low on the north-eastern horizon at around 10pm, gradually moving westwards and staying quite low on the horizon as the night moves on.
In December and January Perseus will be visible from around 10pm appearing low in the north-eastern or northern horizon, over the next few hours it will move westwards before dipping below the north-western horizon.