The eclipsing binary Algol, a bright star in the constellation Perseus, has long been of particular interest to Batman.

 Arab astronomers knew the constellation Perseus as Hamil Ras al-Ghul or He Who Holds the Head of the Devil.

 Perseus, slayer of Medusa, had some very interesting gear: a helmet that made him invisible, winged sandals that allowed him to fly (talarias) a mirror shield, a magic sickle (falx) and a magic bag (kibisis). The invincible Perseus is forever etched in the night sky holding the gorgoneion, head of Medusa, in his left hand, marked by the beautiful and bewitching Algol.

 How many of DC's and Marvel's superheroes (and villains) were lifted directly from the heroes of mythology? Is it true that there are no new stories… only variations upon the themes that were set down so long ago?

 Algol is a variable star, a true eclipsing binary, one of the oldest and best known.  Over the course of about 3 days it noticeably brightens and dims… easily observed with the naked eye –– and clearly this was of interest to ancient astronomers and storytellers. Algol's variability was somehow associated with the dark side — this star is all about "misfortune, violence, decapitation, hanging and incitement to murder… [the] most diabolical and maleficent star of all the stars in the sky" quoting the great astronomer–scholar Giuseppe Sesti from his magnificent Glorious Constellations.

 The name Algol derives from Ras al-Ghul, Head of the Devil. Sound familiar? Every hero needs a villain.

Liam Neeson portrayed Ra's al Ghul in the first film and the third film of The Dark Night Trilogy —Batman Begins and The Dark Knight Rises.