Algieba
HIP 50583; Gamma1 Leo; 41 Leo
Object Data
- Catalog Designation
- HIP 50583; Gamma1 Leo; 41 Leo
- Type
- DoubleStar
- Constellation
- Leo
- Magnitude
- 2.61
- Right Ascension
- 10h 19m 58.3s
- Declination
- +19° 50' 30.0"
- Distance
- 148 light-years
- HR
- 4057
- HIP
- 50583
- Bayer
- Gamma1
Survey Image
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About Algieba
Description
Algieba is one of the finest double stars in the sky at magnitude 2.61 in Leo. A small telescope reveals a stunning pair — a golden-orange giant (K1III, mag 2.3) and a slightly fainter yellow-green companion (G7III, mag 3.5) separated by about 4.5 arcseconds. Located about 126 light-years from Earth, the primary has a confirmed exoplanet.
Observing Tips
Algieba lies in the Sickle of Leo, the curved line of stars forming the Lion's head. In a telescope at 100x or more, it splits into a gorgeous warm-toned double — golden orange and yellowish green. It rivals Almach and Albireo as one of the most beautiful double stars. Best observed February through June.
History
The name Algieba comes from the Arabic 'al-jabhah,' meaning 'the forehead.' The double star nature was first observed in 1782 by William Herschel. In 2009, a giant exoplanet (Gamma Leo b) with about 8.8 Jupiter masses was discovered orbiting the primary.
Fun Facts
Algieba's color contrast — deep gold and pale green — makes it one of the most beautiful doubles in the northern sky. The 'green' star is likely an optical illusion enhanced by contrast with the orange primary, as truly green stars do not exist.