Double star · Ursa Major

Mizar and Alcor

79 UMa

Above the horizon all nightHighest after dark 20:20 · northwest · 34°

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Where is Mizar and Alcor?

Times for LondonChange city

Look northwest, about 34° up at 20:20 in Ursa Major.

Rises: Always up
Highest: 13:28
Sets: Never
Best after dark: 20:20 · 34°

Can I see Mizar and Alcor tonight?

From London tonight, Mizar and Alcor is above the horizon all night. It’s highest soon after dark, around 20:20, in the northwest at 34°.

At magnitude 2.2 it is visible by eye, even from many towns, when the sky is clear.

This is position and timing only: clouds, haze and light pollution aren’t included.

What does Mizar and Alcor look like?

Mizar and Alcor looks white to the eye (color is easier to see in binoculars). Its spectral type is A1.5Vas: white main-sequence star (hotter than the Sun).

Eyes

Look closely at the middle star of the Big Dipper’s handle: a fainter star, Alcor, sits just beside it.

Binoculars

Mizar and Alcor are easily separate, with a fainter star nearby making a small triangle.

Telescope

At 30× or more, Mizar itself splits into two white stars, a classic first double for a new telescope.

What you’re likely to see, not what a space telescope photographs.

About Mizar and Alcor

Mizar and Alcor are a famous pair at the bend of the Big Dipper’s handle. People with good eyesight can see both under reasonably dark skies, and the pair has long been called a test of eyesight.

Mizar was one of the first double stars discovered with a telescope: a small telescope splits it into two white stars. Each of those is itself a close pair, and Alcor has a faint companion too.

Mizar and Alcor are about 80 light-years away and move through space together with most of the Big Dipper’s stars.

Mizar A was also the first star found to be a binary from its spectrum alone, in 1889, and Mizar was among the first double stars photographed.

Mizar and Alcor are a favorite first target for new stargazers. Being able to see the faint star beside Mizar is a quick check of how dark your sky is.

Mizar and Alcor in Ursa Major

Questions

Can I see Alcor without binoculars?

Usually yes, under a reasonably dark sky with normal eyesight. City light makes it harder.

Are Mizar and Alcor really connected?

They are at about the same distance and move through space together. Evidence suggests they are a very wide bound system.

Its constellationUrsa Major Another double starAlbireo Another double starDouble Double 0° awayAlcor 4° awayAlioth GuideStargazing for beginners

Sources: SkyMate; Wikidata (CC0). Positions computed for your place and time with astronomy-engine. Data & Licences