Per - Perseus the Hero

Legend for constellation star maps, IAU and Sky & Telescope magazine (Roger Sinnott & Rick Fienberg), cc-by

Intro and Visual description

Resembles a backward lambda. Located in the Milky Way, between Andromeda/Cassiopeia and Auriga/Taurus. Perseus contains no first-magnitude star, but a pair of beautiful binocular star clusters, known as the Double Cluster. Look for the Perseid meteor shower on August 12.

Usually depicted carrying the detached head of the demon-woman Medusa, or Gorgon, who grew snakes for hair. Perseus married Andromeda after saving her from Cetus with the aid of Pegasus (see Andromeda).

Movies: Clash of the Titans; Internet movie database.

Perseus is included in the ancient star catalogs of Eudoxos of Knidos, Aratos of Soli, and Ptolemy.


Caput Medusae, the Head of the Medusa or Gorgon’s Head.


Special Stars

Mirphak (alpha-Persei). Magnitude: 1.8. Distance: 620 LY.
Algol (beta-Persei), the demon star, the Medusa’s eye. Distance: 95 LY. Magnitude: 2.1 usually, fading every 2.9 days; in four hours it falls to magnitude 3.4; after 20 minutes it brightens. This exact regularity was discovered by G. Montanari in 1669. In 1782 the astronomer John Goodricke correctly suggested that Algol is a binary, with a faint companion that passes in front of Algol periodically making it wink. Following the changes of Algol makes for an interesting night with binoculars or even the unaided eye; check Sky and Telescope for the times of its dimming.


Star Clusters

M34 (Galactic cluster), mag. 5.8.



M76, Little Bumbbell or Cork Nebula (Planetary nebula), mag. 11.4.






Constellation Info

Abbr: Per

Genitive: Persei

Size: 24 of 88

RA: 3 hours

Evening culmination (9 pm): December

Midnight Culmination: November

Decl: 45 degrees

Entirely visible from: N of -31° latitude

Partially visible from: between -59° and -31° latitude

Not visible at all from: S of -59° latitude


Bordering constellations:

Constellation - Names

Arabic: حامل رأس الغول

Chinese: 英仙座

English: Perseus

French: Persée

German: Perseus

Greek: Περσεύς

Hebrew: פרסאוס

Italian: Perseo

Latin: Perseus

Russian: Персей

Spanish: Perseo