If you were to stand at night right at the north pole of the planet, first of all, you would be very, very cold as you would be on top of a thick chunk of ice in the middle of the Arctic Ocean, but you would also notice something curious in the sky. The stars don’t set or rise on the horizon. They simply circle around the zenith (overhead) which is marked by Polaris, the North star.
These stars and constellations, unlike the rest, are not seasonal. They are visible throughout the year in most locations of the northern hemisphere. Circumpolar stars are also the reason for those really cool composite photos of the timelapse of the sky where they rotate around a central point (the magnetic north).
Notice how in the following photo some of the stars never dip below the horizon
This effect happens because as you get closer to the pole, the angle at which you are looking at the area of the sky that contains these stars changes and Earth’s rotation doesn’t “hide” this area anymore.
The following diagram hopefully explains this a bit better.
The southern hemisphere also has its own circumpolar constellations although they are different and they don’t have a star that is as well aligned to the pole as Polaris.
From the equator, there are no circumpolar stars.
Circumpolar constellations in the northern hemisphere
The number of circumpolar constellations you can see is going to depend on your location. The closer you are to the north pole, the more that you will perceive these constellations as circumpolar.
For most people in the US, Canada, and Europe, the circumpolar constellations are the following:
|Ursa Major||Big bear|
|Ursa Minor||Small bear|
|Cepheus||King of Ethiopia in Greek mythology|
|Cassiopeia||Mother of Andromeda in Greek mythology|
If you are closer to the equator around the 30° latitude in places like Florida or Spain, a couple of these constellations might dip below the horizon occasionally.
Circumpolar stars in the northern hemisphere
There are many circumpolar stars in the northern hemisphere. Most of them are going to be inside one of the major constellations listed above.
Only a handful of these stars are visible to the naked eye and their visibility is also going to depend on the sky conditions of your location, the amount of light pollution, weather, etc.
The following tables are going to list the brighter stars that form the main shape of the circumpolar constellations, but please note that those are not all the stars in each of them. Follow the links for a more complete list that includes all the discovered stars for every one of these star formations.
Ursa Major Stars
|Epsilon Ursae Majoris||Alioth|
|Alpha Ursae Majoris||Dubhe|
|Eta Ursae Majoris||Alkaid / Benetnasch|
|Zeta Ursae Majoris||Mizar A & Mizar B|
|Gamma Ursae Majoris||Phecda|
|Delta Ursae Majoris||Megrez|
|Beta Ursae Majoris||Merak|
|Omicron Ursae Majoris||Muscida|
|Nu Ursae Majoris||Alula Borealis|
|Theta Ursae Majoris||Sarir|
|Iota Ursae Majoris||Talitha|
|Mu Ursae Majoris||Tania Australis|
|Lambda Ursae Majoris||Tania Borealis|
|Omega Ursae Majoris|
|Psi Ursae Majoris|
|Chi Ursae Majoris|
|Xi Ursae Majoris||Alula Australis|
Ursa Minor Stars
|Alpha Ursae Minoris||Polaris|
|Beta Ursae Minoris||Kochab|
|Gamma Ursae Minoris||Pherkad|
|Epsilon Ursae Minoris|
|Zeta Ursae Minoris||Ahfa al Farkadain|
|Delta Ursae Minoris||Yildun|
|Eta Ursae Minoris||Alasco|
|Theta Ursae Minoris|
|11 Ursae Minoris||Pherkad Minor|
|Eta Cephei||Al Kidr|
|Mu Cephei||Garnet’s star|
|Xi Cephei A||Kurhah|