Ursa Major & the Big Dipper
Constellation · The Great Bear
The Big Dipper is a pattern of seven bright stars inside the larger constellation Ursa Major, the Great Bear. Two of its stars point straight to the North Star, which makes it one of the most useful star patterns.
- Seven bright starsShape
- The Plough, SaptarishiAlso called
- PolarisPoints to
Take a closer look
The arc to Arcturus
Follow the curve of the Dipper’s handle away from the bowl and you “arc to Arcturus”, a bright orange star. Keep the same curve going and you can “speed on to Spica”, a blue-white star. One star pattern helps you find two more.
Galaxies in the Bear
Point binoculars just beyond the bowl and you may spot two faint smudges: the galaxies M81 and M82, millions of light-years away. M82 is a “starburst” galaxy, making new stars many times faster than our Milky Way. A tug from its bigger neighbour M81 helped set it off.
Six stars, not two
Mizar and Alcor look like a pair, but telescopes reveal much more. Mizar splits into two stars, and each of those is itself a tight pair. Alcor has a small partner too – so this little spot in the handle holds at least six stars.
How we found out
- Ancient India
The seven stars are known as the Saptarishi – the seven great sages.
- Ancient Greece
In Greek myth the stars are the nymph Callisto, turned into a bear and placed in the sky.
- 1800s USA
A famous folk song tells of people escaping slavery by “following the Drinking Gourd” – the Big Dipper – north to freedom.
Will the Big Dipper always look like this?
No – stars move. In about 100,000 years the Dipper will look quite different, because two of its stars are moving in a different direction from the other five.
See it yourself
Northern Hemisphere: look north. Draw a line through the two stars at the end of the “cup” and continue about five times as far to reach Polaris.
From the encyclopedia
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