Constellation · Cep
Cepheus
The King
A circumpolar constellation in the north that holds Delta Cephei, the prototype of the Cepheid variable stars astronomers use to measure distances.
Magnitude 2.45
Highest in the sky at 9 pm local time (autumn in the northern hemisphere)
Latitudes where every part of it rises above the horizon at some time of year
The whole sky covers about 41,253 square degrees
Stars brighter than about magnitude 6, the naked-eye limit under dark skies
Named stars in Cepheus
Brightest first. A lower magnitude means a brighter star.
- Alderamin (Alpha Cephei)mag 2.45
- Errai (Gamma Cephei)mag 3.21
- Alfirk (Beta Cephei)mag 3.23
- Kabalfird (Eta Cephei)mag 3.41
- Al Kidr (Theta Cephei)mag 4.21
- The Garnet Star (Mu Cephei)mag 4.23
Can you see Cepheus from where you live?
This depends only on your latitude. Pick the row nearest to you; for your exact sky tonight, use the sky map.
| Latitude | Cepheus |
|---|---|
| 60°N | Visible all night, all year (it never sets) |
| 40°N | Visible all night, all year (it never sets) |
| 20°N | The whole constellation rises and sets |
| the equator | The whole constellation rises and sets |
| 20°S | Only part of it ever clears the horizon |
| 40°S | Never rises |
| 60°S | Never rises |
Questions about Cepheus
When is Cepheus best seen?
Cepheus stands highest in the sky at 9 pm local time in October. That makes autumn evenings the best time for observers in the northern hemisphere; in the southern hemisphere the season is reversed.
What is the brightest star in Cepheus?
The brightest star in Cepheus is Alderamin (Alpha Cephei), magnitude 2.45.
Where on Earth can you see Cepheus?
The whole of Cepheus can be seen from latitudes between about 1°S and 90°N. From 40°N: Visible all night, all year (it never sets). From 35°S: Only part of it ever clears the horizon.
What does Cepheus mean?
Cepheus is Latin for "the King". One of Ptolemy's 48 ancient constellations (2nd century).