Arcturus Star Facts

• Arcturus is an orange giant star approximately 37 light years from Earth.
• It is part of the Boötes constellation, pronounced boo-oh-tes, meaning herdsmen.
• Arcturus is visible to the naked eye in both the northern and southern hemispheres.
• Arcturus was possibly similar to our sun but has now passed the main sequence period of its lifespan.
• Instead of fusing hydrogen like our sun, Arctutus is now fusing helium in its core, causing it to expand.
• Arcturus is part of the Arcturus Stream, a group of ancient stars which move at a different angle and at a greater speed than other stars in our galaxy.
• The Arcturus Stream is thought to be the remnants of a dwarf galaxy that collided with the Milky Way.
• In around a million years Arcturus will be so far from Earth it will no longer be visible to the naked eye.
• Arcturus is derived from the ancient Greek words arktos, meaning bear, and ouros, meaning guardian.

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Arcturus is an orange giant star with a radius of around 11 million miles (18 million km), which is around 26 times the size of the sun. Arcturus is estimated to have a mass of around 1.1 times that of the sun. Arcturus is estimated to have surface temperatures of around 4000C (7200F), around 73% as hot as the sun. Due to its large size the star's luminosity is between 100 to 200 times greater than that of our sun.

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Also Known As: Alpha Boötes

Distance From Earth: 37 light years

Constellation: Boötes

Star Type: Orange Giant - K Class

Mass: 110% of the Sun

Luminosity: 100 to 200 times the Sun

Diameter: Approx 22 million miles (36 million km) - 26 times the Sun

Temperature: Approx 4000C (7200F)

Age: Approx 10 billion years old

Rotation Period: 2 years

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