Algol, also known as the Demon Star, loses some 70 percent of its light every three days. It's in Perseus the Hero, now ...

Algol is so close to us that we can observe its eclipses with naked eye. These new Algol's companion candidate stars would be literally on our backyard.

ALGOL-60 was extremely limited, though, and as a result there were several rival proposals to modernize the language. One was by a young Swiss computer scientist, the late Niklaus "Bucky" Wirth.

Algol is a short-period variable star. It is usually magnitude +2.3, but regularly, at intervals of two days, 20 hours and 48 minutes, the star’s brightness wanes to minimum light of +3.5.

ALGOL, on the other hand, isn't. The classic ALGOL-60 was once very widely used, and it influenced almost every other imperative programming language in the world today, from Ada to Zonnon.

Thus, Algol has yet another name: “the winking eye of Medusa.” As long as we’re in Halloween/astronomy mode: To the south of Perseus is the constellation Cetus the sea monster.

Algol, also known as the Demon Star, is quite possibly the most interesting star in the fall and winter skies, if you know when to look for its brightness changes.

Algol is a short-period variable star. It is usually magnitude +2.3, but regularly, at intervals of two days, 20 hours and 48 minutes, the star’s brightness wanes to minimum light of +3.5.

Algol C and Algol AB orbit around their common centre of mass. One round takes 1.86 years. The orbital motions of Algol C and Algol AB cause a light travel time effect. We observe the primary eclipses ...