Today we are going to review all the facts about the Perseus Constellation. Learn how to find it and discover the secrets it hides.
What is the Perseus Constellation?
The constellation Perseus is a constellation located in the northern sky. The constellation resembles the Greek hero Perseus who raises his diamond sword above his head with one hand and holds the decapitated head of Medusa in the other. In the 19th century, the constellation was known as Perseus et Caput Medusae. Today, it is called Perseus the hero. Its three-letter abbreviation is Per.
Ptolemy described Perseus and 47 other constellations in the 2nd century. Today, Perseus is one of 88 constellations recognized by the International Astronomical Union. It is the 24th largest constellation in the sky.
How to find the constellation of Perseus
Perseus the hero is not as bright or as easy to recognize as some of the other constellations. Fortunately, it is located near Cassiopeia, the queen, one of the most visible formations in the sky.
To locate Perseus, look to the north, where Cassiopeia forms a bright “W” or “M” (depending on your orientation). If Cassiopeia looks like a “W”, Perseus will be the group of stars below the left side of the zigzag. If Cassiopeia looks like an “M”, Perseus will be the group of stars below the right side of the zigzag.
Once you’ve spotted Perseus, look for its two brightest stars. The brightest is Mirfak, a yellow star at the midpoint of the constellation. The other notable star is Algol, a blue-white star that forms a line with Mirfak to identify the center of the constellation.
The constellations Ares and Auriga (with the bright yellow star Capella) lie to the east of Perseus. Camelopardalis and Cassiopeia are to the north of Perseus, and Andromeda and Triangulum are to the west. Perseus is prominent in the northern sky of the northern hemisphere in the spring, and is also visible in the northern part of the southern hemisphere.
Main stars of the constellation Perseus
Gamma
Without a traditional name, the star is simply known as Gamma Persei, actually a binary system located about 240 light years from Earth, the primary star eclipses the other every 15 years causing it to appear darker in the night sky for a couple of weeks.
Mirfak
Also known as Alpha Persei, Mirfak is located about 500 light years from Earth and is the brightest star in the constellation, it is a white supergiant with a diameter about 30 times that of the sun.
Algol
Also known as Beta Persei, Algol is actually a three star system located about 90 light years from Earth, the primary star is eclipsed by one of its less bright companions every 3 days causing its brightness to drop considerably for several hours. In the late 18th century, the star was the first eclipsing binary to be discovered. Historically Algol has been referred to as the “Demon Star”, this may be because the ancients perceived its dimming in brightness as an omen of bad luck.
Gorgonaceae
Also known as Rho Persei, Gorgonea Tertia is a red giant about 300 light-years from Earth, 150 times larger in diameter than the sun.
Epsilon
Epsilon Persei is a binary or possibly triple system 640 light years from Earth, the primary star has surface temperatures 5 times higher than the sun with a mass about 14 times greater.
Zeta
Zeta Persei is a blue supergiant about 750 light-years from Earth, it is more than 25 times larger in diameter than the sun and nearly 50,000 times more luminous.
Key stars in the constellation of Perseus
There are 19 stars in the main asterism of the constellation, but in areas with light pollution only two of them (Mirfak and Algol) are bright. Notable stars in the constellation include:
- Mirfak: the brightest star in Perseus is a yellow-white supergiant. Other names for this star are Mirphak and Alpha Persei. Mirfak is a member of the Alpha Persei group. Its magnitude is 1.79.
- Algol: also known as Beta Persei, Algol is the best known star in the constellation. Its variable brightness is easily seen with the naked eye. Algol is not, however, a true variable star. It is an eclipsing binary that varies in magnitude from 2.3 to 3.5 over a period of 2.9 days. Algol is sometimes referred to as the Demon Star. The color of its primary star is blue-white.
- Zeta Persei: The third brightest star in Perseus is a blue-white supergiant with a magnitude of 2.86.
- X Persei: This is a binary star system. One of its two members is a neutron star. The other is a bright, hot star.
- GK Persei : GK Persei is a nova that reached its maximum brightness in 1901 with a magnitude of 0.2. Seven of the stars in the constellation are known to have planets.
Deep sky objects in the constellation Perseus
Perseus lies in the galactic plane of the Milky Way, but the galaxy is not very obvious in this region. The constellation contains interesting deep sky objects, including several nebulae and the Perseus cluster of galaxies.
Highlights in the constellation
- NGC 869 and NGC 884 : Together, these two objects form the Double Cluster. The double star cluster is easily observed with a small telescope.
- M34 : M34 is an open cluster that can be seen (barely) with the naked eye and is easily resolved with a small telescope.
- Abell 426: Abell 426 or the Perseus cluster is a massive group of thousands of galaxies.
- NGC 1023: This is a barred spiral galaxy.
- NGC 1260: This is a closed spiral galaxy or lenticular galaxy.
- Small dumbbell nebula (M76) : This nebula looks like a dumbbell.
- California Nebula (NGC 1499) : This is an emission nebula that is difficult to observe visually, but takes on the shape of the state when viewed through a telescope.
- NGC 1333: This is a reflection nebula.
- Perseus molecular cloud: This giant molecular cloud blocks much of the light from the Milky Way, making it appear dark in this region of space.
The Perseid meteor shower
The Perseid meteor shower appears to radiate from the constellation Perseus. Meteors can be seen beginning in mid-July and peaking in mid-August. The meteors are debris from the Swift-Tuttle comet. At its peak, the shower produces 60 or more meteors per hour. The Perseid shower sometimes produces bright fireballs.
Perseus constellation mythology
Perseus was a Greek mythological hero whose adventures provide the backstories for other constellations. He was fathered by the King of the 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 kill him. After Perseus was born, the King placed his daughter and newborn grandson in a wooden chest and sent them drifting out to sea. The pair survived and landed safely on an island, where they were taken in by a local nobleman who raised the young hero during his infancy.
Once Perseus reached adulthood, the nobleman sent him on his most famous adventure, to kill 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 help of mirrors. Perseus finally killed the King of Argos, accidentally hitting him on the head with a javelin in an athletic competition.
Facts about the constellation of Perseus
- Perseus is a constellation in the northern sky.
- The constellation is named after the Greek mythological hero and demigod Perseus, known for slaying the Gorgon Medusa.
- The constellation Perseus is quite faint and difficult to see in light polluted areas. Its two brightest stars are Mirfak and Algol.
- The Perseid meteor shower radiates from the constellation in July and August.
