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Bellatrix

HIP 25336; Gamma Ori; 24 Ori

HIP 25336; Gamma Ori; 24 Ori DoubleStar Ori Visible Level 3 Medium telescope (6-8") - Requires steady seeing
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Physical Properties

Magnitude 1.64
Spectral Type B2III
Star Color Blue (B-V -0.22)
Temperature 22604 K
Radius 5.7 R☉
Distance 239.8 ly

Position & Identifiers

RA 05h 25m 07.9s
Dec +06° 20' 59.0"
Constellation Ori
HR 1790
HIP 25336
Bayer Gamma
Flamsteed 24 Ori

Visibility

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Multiple Star System

Separation 178.0″
Companion Mag 13.1
Position Angle 144°
Star Colors A: Blue
Discoverer BUP 78

Eyepiece View

32x Dawes: 1.9″ TFOV: 1.6°
Realistic = true angular size
N E 144° A (1.6) B (13.1)

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

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Blackbody Spectrum

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

Stellar Notes

Ori OB1.
Expanding circumstellar shell. AEROBEE evidence for mass ejection up to 1600k/s.
BELLATRIX; the Amazon Star.
Diam. = 0.00070 - 0.00072".

Survey Image

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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.