Bellatrix
HIP 25336; Gamma Ori; 24 Ori
Physical Properties
Position & Identifiers
Visibility
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Multiple Star System
Eyepiece View
Sep: 178.0″ · PA: 144° · N up, E left
Resolved · Rayleigh: 2.3″ · Dawes: 1.9″ · Eff: 3.1″
Size Comparison
Stellar Lifecycle
Spectral Classification
Hertzsprung-Russell Diagram
Blackbody Spectrum
Stellar Absorption Spectrum
Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.
Stellar Notes
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About Bellatrix
Description
Bellatrix is a blue giant of spectral type B2III, the third brightest star in Orion at magnitude 1.64. Located about 250 light-years from Earth, it marks Orion's left shoulder (as viewed from our perspective). Bellatrix is about 8-9 times the mass of the Sun and roughly 9,200 times more luminous. It is one of the hottest stars easily visible to the naked eye, with a surface temperature of about 22,000 K.
Observing Tips
Bellatrix is found at the upper right corner of Orion's rectangle of body stars, opposite the red supergiant Betelgeuse. While not as famous as its fellow shoulder star, Bellatrix's blue-white brilliance contributes to Orion's striking visual impact. The contrast between Bellatrix's blue-white color and Betelgeuse's red-orange across the constellation is beautiful. Best observed from November through March.
History
The name Bellatrix is Latin for 'the female warrior,' sometimes translated as 'the Amazon Star.' In medieval Arabic astronomy, it was known as 'al-Najid' meaning 'the conqueror.' Bellatrix was one of the navigation stars used by European sailors. It has been evolving away from the main sequence and will eventually become an orange giant before ending its life, possibly as a supernova if massive enough.
Fun Facts
Bellatrix is near the mass threshold that separates stars that end as white dwarfs from those that explode as supernovae — its ultimate fate depends on exactly how much mass it retains as it evolves. It is the 26th brightest star in the sky and the third brightest in one of the sky's most iconic constellations.