Betelgeuse is the brightest star in Orion and marks the western shoulder of the constellation. Betelgeuse is one of the largest known stars and is probably at least the size of the orbits of Mars or Jupiter around the sun. That's a diameter about 700 times the size of the Sun or 600 million miles. For a star it has a rather low surface temperature (6000 F compared to the Sun's 10,000 F). The low temperature means that the star will appear orange-red in color.

Betelgeuse emits almost 7,500 times as much energy as the Sun. The combination of size and temperature tells astronomers that the star is a kind of star called a red super giant. Red super giants are stars that are close to the end of their life. Probably within the next ten to hundred thousand years Betelgeuse might end its life in a supernova explosion.

The name Betelgeuse comes from the Arabic and is basically a corruption of the phrase "Armpit of the Giant". The star's distance implies that it is not at the same distance as many of the other stars in Orion.

Fact Table

Name Betelgeuse
Object Star -- Evolved -- Red Super Giant
Distance 520 light years
Diameter 700 Million miles
Brightness 7,500 times greater than the Sun
6000 F
Color Orange-red
Mass 20 x the mass of the Sun

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Ronald J. Maddalena 1998