Polaris

The north star. It stays still while all the others go round it. It is not one of the brightest stars at all — it is famous only for standing still, because the Earth's axis happens to point almost straight at it.

Also called: the North Star, the Pole Star.

🕒 When can I see it?🚀 Travel there

What it is

Yellow-white supergiant sitting near Earth's north celestial pole; also a Cepheid variable.

Star: A ball of gas with enough mass to fuse hydrogen in its core. Every kind of thing there is →

How to find Polaris

Look in the constellation Ursa Minor.

It is best placed all year round if you are north of the equator.

Circumpolar; never rises south of the equator.

Finding it: The tip of the Little Dipper's handle.

The Planetarium works out where it actually is from your own place and the date — including whether it is above the horizon at all tonight.

Show me Polaris in tonight's sky

What you will really see

With your own eyes

A bright point of light — even big telescopes can't show a star as a disc.

🔭 See it drawn as it looks through a telescope

🖨️ A sheet to print for this

🖨️ Print a sheet and go and look

🖨️ Sheet to take outside →

Worth knowing about Polaris

In weight, about 5 times as massive as the Sun. On the 100-meter-track scale model of the Milky Way, Polaris would be a little under half a meter from the Sun. Light takes 433 Earth years to get here from Polaris, so what you are looking at is Polaris as it was 433 Earth years ago.

How bright it is: A true supergiant — shines well over a thousand times brighter than the Sun.
What it is made of: A yellow-white supergiant, also a Cepheid variable — a star that pulses in size and brightness on a precise schedule.
How far away it is: Polaris is one of the best-measured distances in the sky — and its light left the star centuries before anyone alive today was born.; How we know: Distance found by parallax, cross-checked against the pulsation-brightness relationship used for far more distant Cepheids. Rung 6 of the cosmic ladder — the distance to other galaxies
What makes it worth knowing: Cepheid variables are cosmic yardsticks: longer pulse cycle means more luminous, letting astronomers measure distances even to other galaxies.