In the northeastern sky this evening, in the constellation Perseus the hero, there is a star named Algol. Algol is not particularly bright, but it is quite an unusual star – three stars, actually. The name Algol derives from its Arabic designation as “the demon,” and is also the basis of the word, “ghoul.” Algol is a trinary star system, and two of the stars are so aligned with our planet that about every three days, we can observe one star pass directly in front of the other, an eclipsing binary. When that happens, the light from this triple star dims. To the ancients, this was like the winking of a demon’s eye. Algol was thus portrayed as the eye of the snaky-haired gorgon Medusa, whose glance could turn anyone who looked upon her into stone. While you can’t look at a gorgon, you can certainly watch tonight’s meeting of the Treasure Coast Astronomical Society, which will be at 7:30 this evening at the IRSC Science Center in Fort Pierce; come on out and see the stars!