Cepheus
Origin
Cepheus is a constellation located in the northern hemisphere, neighboring the constellations Camelopardalis, Cassiopeia, Cygnus, Draco, Lacerta, and Ursa Minor. It is the 27th-largest constellation in the night sky and occupies an area of 588 square degrees. Cepheus is named after the Greek mythological king Cepheus of Ethiopia who was married to Cassiopeia and father of Andromeda, both nearby constellations in the sky.
Bright Stars
Delta Cephei is a variable star which ranges from magnitude 3.5 to 4.4 and is the prototype Cepheid variable star, a class of variable star for which the period of its pulsations is directly related to its mass and therefore absolute brightness. This means that Cepheid variables are useful as cosmic yardsticks since astronomers can approximate a Cepheid’s absolute brightness based on its period and use that brightness to determine the star’s distance (in the case of Delta Cephei its period is 5 days and 9 hours and it is about 980 light-years away from us).
Photo of the constellation Cepheus produced by NOIRLab in collaboration with Eckhard Slawik, a German astrophotographer.
The annotations are from a standardized set of 88 western IAU constellations and stick figures from Sky & Telescope. Please find here a non-annotated version of the image.
Credit: E. Slawik/NOIRLab/NSF/AURA/M. Zamani
Latin name
English name
Cepheus
Pronunciation
SEE-fee-us
Abbreviation
Cep
Notable Objects
Cepheus has numerous deep-sky objects such as the Wizard Nebula (NGC 7380), the Iris Nebula (NGC 7023), and the Fireworks Galaxy (NGC 6946). Another popular object is Mu Cephei, which is a variable star that varies between magnitude 3.43 and 5.1 and is also called Herschel’s Garnet Star because of its distinctive garnet red color. Mu Cephei is a red supergiant and one of the largest stars known. It shines about 100,000 times brighter than our Sun (if it were at the same distance away, but Mu Cephei is about 3,000 light-years away.)
