Persée (constellation)

See also: Persée (homonymy)

Persée is a Constellation of the northern Hemisphere. Relatively large, it has several star S brilliant, of which the variable star Algol (β  Persei).

History and mythology

The constellation of Persée is old. Already indexed by Ptolémée in its Almageste at the 1st century, it is supposed to represent Persée, the hero of the Greek Mythologie which saved Andromède. The constellation belongs to the cycle which describes the myth of Andromède (to refer to it).

Observation of stars

; Location of the constellation Persée is a very luminous constellation, placed in a very rich environment.
  • Its position can be located by taking the alignment which leaves the Grand square of PEGASE and goes up along the diagonal of Andromède until Algol of Persée and Capella of the Cocher.
  • Conversely, one can start from Capella, the most brilliant star of the area, and locate its neighbors Algol (β Per) and Mirfak (α Per) in direction of the West.
  • One can be also located compared to Cassiopée, while following the alignment of the median bar of sound " W" in direction of South-east, alignment which falls on Mirfak (α Per).
  • One can finally go up the alignment which starts from Rigel in Orion, passes by Aldébaran of the Taureau, and fall on Algol (β Per) before joining Cassiopée in the axis of the right-hand man of sound " W".

; Form constellation Although made of relatively brilliant and brought closer enough stars, Persée does not release from very clear form. When the conditions of visibility are good, one can recall the general shape of a star with five branches (the body), with which four are equipped with appendices (members).

The first two visible stars are Mirfak (α Per), which marks the neck of Persée, and ALGOL (β Per), more in the South, which mark the Western foot. One quickly sees then appearing ε Per in the South (the foot East) and γ Northern Per side (the point of the hat).

The brilliant star located in the middle of the Western arm, θ  Persei, is sometimes regarded as component the sword of Persée. The limit of the constellations between Persée and andromède is very notched in this zone, the " main" of Persée which almost seems to seize the " pied" from Andromède extends beyond from a zone which belongs already to the latter.

Persée is generally drawn holding in its hand the head of Méduse and this one is represented by Gorgonea Secunda (π  Per), Gorgonea Tertia (ρ  Per) and Gorgonea Quarta (ω  Per), ALGOL (β  Per) - “ Gorgonea Preceded ” - formant as-with it the eye of the Gorgone. These four stars are those which form the " pied" immediately in the south of ALGOL.

Principal stars

See also: List of stars of Persée

Mirphak (α  Persei)

Mirphak (α  Persei) is the most brilliant star of the constellation. With a Magnitude connect of 1,79, it is classified 35e most brilliant stars of the sky. Distant of almost 600 light-years of our Solar system, it is a Supergéante 60 times larger than the Sun.

It is sometimes named “ Algenib ”.

ALGOL (β  Persei)

ALGOL (β  Persei) is the second star of the constellation by the most known luminosity, but. It is the prototype of the variable stars of standard Algol, which are actually double stars where one of the components eclipse periodically more shining. ALGOL passes thus from magnitude 2,12 to the magnitude 3,39 every 2,867 days.

Other stars

A last star of the constellation bears a proper name: Misam (κ  Persei).

In 1901, the Nova GK Persei appeared several degrees in lower part of Mirphak.

Celestial objects

Close to γ  Persei is the radian of the “ Perséides ”, a swarm of Météoroïde S which causes each year a “rain” of shooting stars in the neighborhoods of the 12 August (also called Larmes from Saint Laurent, whose festival falls on August 10th).

One can also note the celestial objects following in the constellation of Persée, crossed by the Milky Way:

  • h+χ Persei: Two open Clusters S (NGC 869 and NGC 884 respectively), distant moreover 7.000 years light of the solar system and separate one and the other by several hundreds of years light.

  • M34 : cluster open of magnitude connect 5,5 (visible with the naked eye if the night is very dark), distant of approximately 1.400 years light and formed of a hundred stars distributed in a Sphère 14 years light of diameter.
  • M76 : a Nebulous planet gear.
  • NGC 1499 : a Nebulous in emission called “ Nebulous California ”.

See too

  • List of stars of Persée

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