Polaris Star Facts

• Polaris is approximately 430 light years from Earth and is the brightest star in the constellation of Ursa Minor.
• Polaris is a three star system comprising of the supergiant Polaris A and two smaller companions.
• The two companion stars, Polaris Ab and Polaris B, are both yellow-white dwarfs with similar surface temperatures to their giant neighbor.
• Polaris Ab is around 2 billion miles (3.2 billion km) from Polaris, Polaris B orbits at a distance of around 240 billion miles (389 billion km).
• A further two distant stars may be associated with Polaris, which would make it a five star system.
• Polaris is the only star in the night sky that appears to remain stationary, this is because it is currently positioned above the northern axis of Earth's rotation.
• As the star always points north it has been an aid to navigators for centuries, although it is only visible in the northern hemisphere.
• Polaris has been aligned above the North Pole for around 2,000 years but after 2100 Earth's northern axis will begin to move away from the star.

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Polaris is a white supergiant star with a radius of around 22 million miles (35 million km), which is around fifty times the size of the sun. Polaris is estimated to have a mass of around 4.5 times greater than that of the sun. Polaris has surface temperatures of around 5,700C (10,300F), which is similar to the surface temperature of the sun. Due to its larger surface area Polaris has a luminosity around 2,500 times greater than that of our sun.

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Also Known As: Polaris A, Alpha Ursae Minoris, Pole Star, North Star

Distance From Earth: 430 light years

Constellation: Ursa Minor

Star Type: F Class Supergiant

Mass: 4.5 x Sun

Luminosity: 2,500 x Sun

Diameter: 44 million miles (70 million km) - 50 x Sun

Temperature: 5,700C (10,300F)

Age: Unknown

Rotation Period: 119 days

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