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Algieba (Gamma Leonis)





Algieba (Gamma Leonis)
Gamma Leonis
Photo credit: Rainer Anton

The third brightest star in the constellation Leo. Algieba is a magnificent binary system with orange-red and yellow components visible through a modest telescope under good atmospheric conditions; its Arabic name means "the forehead". The brighter component (magnitude 2.6) is a giant K star with a surface temperature of 4,400 K and a luminosity of 180 Lsun; its partner is a magnitude 3.8 giant G star with a temperature of 4,900 K and a luminosity of 50 Lsun. The angular separation of just over 4" means that the two stars are at least 170 AU apart – four times the Pluto-Sun distance – and have an orbital period of over 500 years.


visual magnitude 2.01
absolute magnitude -0.92
spectral type K0III + G7III
distance 126 light-years (39 pc)
position R.A. 10h 19m 58.3s,
Dec. +19 50' 30"
other designations 41 Leo, BD +202467, HD 89484,
LTT 12764/12765, GCTP 2423.00,
SAO 81298, ADS 7724, HIP 50583


Related category

   • NOTABLE STARS