Both northern and southern hemisphere stargazers are treated to many striking constellations that are visible any night of the year – the northern and southern polar constellations. These constellations are what’s called circumpolar, meaning they never rise or set. That’s very handy, since it means they are above the horizon all year, and are visible all night, so you’ll soon get used to finding them and using them as signposts to other constellations.
Stargazing: Northern polar constellations
The six northern polar constellations are near the North Star, so you’ll only be able to see all of them if you’re stargazing in the northern hemisphere. If you were at the North Pole, they’d be spinning directly overhead, but for northern hemisphere observers they spin in an anticlockwise direction around the North Star. The six northern polar constellations, as shown in the figure, include:
Ursa Major, the Great Bear
Cassiopeia the Queen
Ursa Minor, the Little Bear
Draco the Dragon
Cepheus the King
Camelopardalis the Giraffe
These constellations, when observed from northern latitudes, are circumpolar, meaning they never rise or set. That’s very handy because it means they’re above the horizon year-round and are visible all night, so you’ll soon get used to finding them and using them as signposts to other constellations.
Where in the sky you have to look depends on where on Earth you’re stargazing. The northern polar constellations all appear towards the north of the sky, but the closer you are to the North Pole, the higher they are. In fact, the North Star’s altitude above the northern horizon is equal to the latitude you’re stargazing from.
Stargazing: Southern polar constellations
The stars around the southern pole form some striking constellations, such as the Southern Cross, and there are a wealth of great objects to look for, like the Large and Small Magellanic Clouds. The figure shows a map of these constellations, which include the following:
Crux (Southern Cross)
Apus
Chamaeleon
Circinus
Dorado
Hydrus
Mensa
Musca
Norma
Octans
Pavo
Triangulum Australe
Tucana
Volans
Remember that as the Earth spins, the position and orientation of the constellations changes. The maps show their relative positions next to one another. Check monthly star maps for your location to find out where in the sky the constellations actually appear.
