Categories: Astronomy ListsStars

Betelgeuse Interesting Facts

Credit & Copyright: Rogelio Bernal Andreo at www.deepskycolors.com

Located In Orion Constellation

Betelgeuse is a red supergiant star located 640 light-years away in the constellation of Orion. This distinctive star is found in the upper-left corner of Orion and marks the hunter’s right shoulder.

Name Means ‘Hand Of The Central One’

The name Betelgeuse is derived from the Arabic ‘yad al-jawza’ meaning ‘hand of the central one’ However, in  medieval times the “y” was mistranslated as a “b” hence the star’s unusual name. Interestingly, Arab astronomers initially saw the central one (‘Jauza’) as the nearby constellation of Gemini, but after studying Greek astronomy switched its name to refer to the constellation of Orion.

1,000 Times Bigger Than Our Sun

Betelgeuse is a huge variable star that fluctuates in size from between 700 times to 1,000 bigger than the Sun. If it replaced the sun in our own solar system it would reach the Asteroid Belt, and extend to the orbit of Jupiter.

Fluctuates In Brightness

Being an irregular variable Betelgeuse also fluctuates in brightness and although it has a luminosity around 13,000 times that of the sun, its brightness ranges between 0.2 and 1.2 magnitude in the night sky. Consequently, despite being the 8th brightest star in the celestial heavens there are periods when it outshines even Orion’s brightest star Rigel, while at other times it appears fainter than the 19th brightest star Deneb in the constellation Cygnus.

A Red Supergiant Star

Stars change color throughout  their life-cycle from the hottest blue types to the older, cooler red types depending on which phase of its stellar evolution has been reached. Betelgeuse is old for a supergiant and has a low surface temperature of 6000 F, making it appear orange-red in colour. Interestingly, the Greek astronomer Ptolemy (90AD – 168AD) observed its colour as “ruddiness,” but three centuries earlier Chinese astronomers described Betelgeuse as appearing yellow, perhaps suggesting Betelgeuse may have been a yellow supergiant just a couple of thousand years ago.

Just 10 Million Years Old

A peculiar fact about massive stars is that they burn through their fuel much faster than other stars and are extremely short-lived.  At just 10 million years of age, Betelgeuse is already quite old for a supergiant and near the end of its life. In contrast, our sun is a yellow dwarf star 4.5 billion years old which is expected to last another 6 billion years.

Betelgeuse Could Go Supernova

As a star gets older it quickly burns out its hydrogen fuel,  and then switches to helium and other elements. During this expanding and cooling stage the star is called a giant, but during fusion heavier and heavier atoms are created until its core is iron, at which point it runs out of fuel. If that star is sufficiently massive, like Betelgeuse, the entire star collapses and explode as a supernova. In fact, it is possible Betelgeuse has already gone supernova, and that the light will not reach Earth for centuries as Betelgeuse is located 640 light-years away.

640 Light-years Distant

When Betelgeuse does finally go supernova, it will present a truly spectacular sight from Earth and could resemble the picture above. The blast of light will appear as bright as the full Moon and be visible in daylight for many months. However, it’s radiation is unlikely to affect the Earth as to be harmful a supernova would have to be no further than 25 light years away, and Betelgeuse is a safe 640 light-years distant from us.

Peter Christoforou :