WhatTheStar

Stars · Star in Ursa Minor

Star

Polaris

The North Star. Not the brightest — about fiftieth — but the one that doesn’t move. Its height above your horizon is your latitude.

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Constellation
Ursa Minor
Designation
α Ursae Minoris
Apparent magnitude
1.97 · 48th brightest star in the night sky
Spectral class
F7:Ib-IIv SB
Distance
433 light-years
Position (J2000)
RA 2h 32m · Dec +89° 16′

A yellow-white star, around 6,500 K, like Procyon. About 65× brighter than the faintest star the eye can see. The light you are seeing left around 1593.

Look for

Follow the Big Dipper’s Pointers five times their gap. Everything else in the northern sky wheels around it.

History

It has not always been the pole star. In 2700 BC it was Thuban, and in 14,000 AD it will be Vega.

Science

Polaris is a Cepheid variable, pulsing gently every four days, with two companions.

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Its constellation

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All stars · Field guide · Open the sky map

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