2.12
Apparent Mag90
Distance (ly)B8V
Spectral Type13,000
Temperature (K)Algol is the prototype eclipsing binary star. Its regular dimming every 2.87 days was known to ancient astronomers who associated it with ill omen.
Stellar Data
Apparent Magnitude2.12
Absolute Magnitude-0.07
Distance90 light-years
Spectral TypeB8V
Temperature13,000 K
Luminosity98 L☉
Radius2.73 R☉
Mass3.17 M☉
Right Ascension03h 08m 10.1s
Declination+40° 57′ 20.3″
ConstellationPerseus
Notable Facts
- Algol dims by over a magnitude every 2.87 days
- Ancient Arabs called it the Demon Star (Ra's al-Ghul)
- The Algol paradox helped understand mass transfer in binary stars