The brightness of variable stars, exemplified by Algol (Beta Persei), can be estimated by comparing their visual magnitude to nearby stars of known magnitudes. Algol, an eclipsing binary star system, ...

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Ancient Egyptian astronomers may have discovered variable stars, and calculated the period of a well-known one called Algol, thousands of years before Europeans. But they buried those observations in ...

Lauri Jetsu, an astrophysicist at the University of Helsinki, is following a tradition that may stretch back thousands of years. For more than a decade, he’s studied the bright star Algol, one of the ...

There is a group of variable pairs of stars known as Algol-type binaries. They are named after the prototype member of this class: Algol, a bright multiple star system in the Perseus constellation. In ...

Here’s a little astronomical riddle for you: Which star in the late-autumn sky winks at us once every 2 days, 20 hours, and 49 minutes? Each wink lasts about 10 hours. If you identified the mystery ...

The Ancient Egyptians were meticulous astronomers and recorded the passage of the heavens in extraordinary detail. The goal was to mark the passage of time and to understand the will of the Gods who ...

A lovely constellation that straddles the Milky Way is Perseus, the hero, which is visible in the northern skies from July to March. Its stars arc from Capella, in the constellation Auriga, to the "W" ...

Everyone has seen stars twinkling in the night sky. The flickering is produced by turbulence in Earth's atmosphere that temporarily deflects the narrow beams of starlight before they reach our eyes.

ON the evening of October 29, while examining the Pleiades with a binocular at about 9 p.m., G.M.T., I noticed that the star Atlas (27 Tauri) was slightly fainter than Pleione (28 Tauri), a little to ...