Algol

Algol, designated Beta Persei (β Persei, abbreviated Beta Per, β Per), known colloquially as the Demon Star, is a bright multiple star in the constellation of Perseus. It is the first and best known eclipsing binary, and one of the first non-nova variable stars to be discovered. An Ancient Egyptian Calendar of Lucky and Unlucky Days composed some 3,200 years ago is claimed to be the oldest historical document of the discovery of Algol. The association of Algol with a demon-like creature (Gorgon in the Greek tradition, ghoul in the Arabic tradition) suggests that its variability was known long before the 17th century, but except for the Ancient Egyptian discovery there is still no indisputable evidence for this.

Historically, the star has received a strong association with bloody violence across a wide variety of cultures. In the Tetrabiblos, the 2nd-century astrological text of the Alexandrian astronomer Ptolemy, Algol is referred to as "the Gorgon of Perseus" and associated with death by decapitation: a theme which mirrors the myth of the hero Perseus's victory over the snake-haired Gorgon Medusa. Astrologically, Algol is considered one of the unluckiest stars in the sky, and was listed as one of the 15 Behenian Fixed Stars.

The Behenian Fixed Stars are a selection of fifteen stars considered especially useful for magical applications in the medieval astrology of Europe and the Arab world.

Etymology
The name Algol derives from Arabic رأس الغول raʾs al-ghūl : head (raʾs) of the ogre (al-ghūl) (see "ghoul"). The English name "Demon Star" is a direct translation of this.

In Hebrew folklore, Algol was called Rōsh ha Sāṭān or "Satan's Head", as stated by Edmund Chilmead, who called it "Divels head" or Rosch hassatan. A Latin name for Algol from the 16th century was Caput Larvae or "the Spectre's Head".Hipparchus and Pliny made this a separate, though connected, constellation.

In Chinese, 大陵 (Dà Líng), meaning Mausoleum, refers to an asterism consisting of β Persei, 9 Persei, τ Persei, ι Persei, κ Persei, ρ Persei, 16 Persei and 12 Persei. Consequently, β Persei itself is known as 大陵五 (Dà Líng wu, English: The Fifth Star of Mausoleum.). According to R.H. Allen the star bore the grim name of Tseih She 叠尸 (Dié Shī), meaning "Piled up Corpses" but this appears to be a misidentification, and Dié Shī is correctly π Persei, which is inside the Mausoleum.

Algol or Medusa Head Archetype
Algol, also known as the Demon’s head, has been misunderstood by a fearful patriarchy who saw this star as the most evil star in the sky. Algol symbolises the head of the Gorgon, Medusa, a misjudged beauty whose conscious coupling with Poseidon within a sacred temple brought down the wrath of her righteous, jealous sister who transformed her into an ugly hag; whose glaring eyes would turn anyone to stone; whose menstrual blood either killed or healed whoever it touched; and whose serpent hair both symbolised energy and fertility (on the head hair signifies higher spiritual forces, and below the waist it indicates the fertilizing forces). Algol/ Medusa depicts everything that Man fears in life, the fury of the suppressed feminine soul; the rage and violence of nature; the fine line between madness and wisdom and life and death; the depth and power of a woman’s sexuality.