Algol
the winking demon star
Today this word meansThe second-brightest star in Perseus. Its brightness dims on a regular cycle.
In the constellation figure, this star sits at the head of Medusa in Perseus's hand.
The name Algol comes from Arabic raʾs al-ghūl, "the head of the ghoul."
Every 2.87 days it dims noticeably for a few hours — an eclipse, two stars taking turns blocking each other. That flicker made it an ill-omened star in culture after culture.
Worth noting
The star's name is Arabic, not mythological. But its position marks Medusa's eye — striking that two traditions found the same spot sinister.