Pi2 Cygni
Encyclopedia
Pi² Cygni is a fourth-magnitude star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

 in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 Cygnus
Cygnus (constellation)
Cygnus is a northern constellation lying on the plane of the Milky Way. Its name is the Latinized Hellenic word for swan. One of the most recognizable constellations of the northern summer and autumn, it features a prominent asterism known as the Northern Cross...

. It has the traditional name Pennae Caudalis, which is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for "Tail Feathers" (of Cygnus the Swan
Swan
Swans, genus Cygnus, are birds of the family Anatidae, which also includes geese and ducks. Swans are grouped with the closely related geese in the subfamily Anserinae where they form the tribe Cygnini. Sometimes, they are considered a distinct subfamily, Cygninae...

). Another name is Sama al Azrak (Arabic
Arabic language
Arabic is a name applied to the descendants of the Classical Arabic language of the 6th century AD, used most prominently in the Quran, the Islamic Holy Book...

 السماء الازرق ~ as-sama al-azraq), meaning "The Blue Sky".

In Chinese
Chinese language
The Chinese language is a language or language family consisting of varieties which are mutually intelligible to varying degrees. Originally the indigenous languages spoken by the Han Chinese in China, it forms one of the branches of Sino-Tibetan family of languages...

, , meaning Flying Serpent
Flying serpent (asterism)
Flying Serpent is an asterism in the Chinese constellation Encampment .The Jin Shu describes this asterism as: "Flying/Ascending Serpent, 22 stars north of the Ying "Camp" constellation, [a.k.a.] Heavenly Snake, chief of the water reptiles."...

, refers to an asterism consisting of π2 Cygni, α Lacertae
Alpha Lacertae
Alpha Lacertae is an A-type main sequence star in the constellation of Lacerta...

, 4 Lacertae, π1 Cygni
Pi1 Cygni
Pi1 Cygni is a star in the constellation Cygnus. It has the traditional name Azelfafage.In Chinese, , meaning Flying Serpent, refers to an asterism consisting of π1 Cygni, α Lacertae, 4 Lacertae, π2 Cygni, HD 206267, ε Cephei, β Lacertae, σ Cassiopeiae, ρ Cassiopeiae, τ Cassiopeiae, AR...

, HD 206267
HD 206267
HD 206267 is a star....

, ε Cephei
Epsilon Cephei
Epsilon Cephei is a Class F0, fourth-magnitude star in the constellation Cepheus. Epsilon Cephei is a yellow-white, Delta Scuti variable star, located about 85 light-years from Earth....

, β Lacertae, σ Cassiopeiae
Sigma Cassiopeiae
Sigma Cassiopeiae is a binary star in the constellation Cassiopeia. It is approximately 1520 light years from Earth and is a combined apparent magnitude of +4.88....

, ρ Cassiopeiae
Rho Cassiopeiae
Rho Cassiopeiae is a yellow hypergiant star in the constellation Cassiopeia. It is about away from Earth, yet can still be seen by the naked eye , as it is 550,000 times as luminous as the Sun. On average, it has an absolute magnitude of −7.5, making it one of the most luminous stars known...

, τ Cassiopeiae
Tau Cassiopeiae
Tau Cassiopeiae is a star in the constellation Cassiopeia.τ Cassiopeiae is an orange K-type giant with an apparent magnitude of +4.88. It is approximately 172.8 light years from Earth....

, AR Cassiopeiae
AR Cassiopeiae
AR Cassiopeiae is a multiple star system in the constellation of Cassiopeia. It is thought to be a septuple star system. It is only one of two star systems with a multiplicity of 7, the other being Nu Scorpii, with no physical multiple stars of greater multiplicity yet found.The star was...

, 9 Lacertae, 3 Andromedae
3 Andromedae
3 Andromedae is a star in the constellation Andromeda. Its apparent magnitude is 4.64....

, 7 Andromedae
7 Andromedae
7 Andromedae is a star in the constellation Andromeda. Its apparent magnitude is 4.53....

, 8 Andromedae
8 Andromedae
8 Andromedae is a red giant star in the constellation Andromeda. Its apparent magnitude is 4.85.-Component:-References:#...

, λ Andromedae
Lambda Andromedae
Lambda Andromedae is a binary star in the constellation Andromeda. It is approximately 84.2 light years from Earth....

, κ Andromedae
Kappa Andromedae
Kappa Andromedae is a star in the constellation Andromeda.Kappa Andromedae is a blue-white B-type subgiant with an apparent magnitude of +4.15. It is approximately 170 light years from Earth.-References:*...

, ψ Andromedae
Psi Andromedae
Psi Andromedae is a double star system in the constellation Andromeda. It is approximately 1310 light years from Earth. The system consists of a spectroscopic binary with a yellow G-type supergiant and a white A-type main sequence dwarf. It has a combined apparent magnitude of +4.97.-References:*...

 and ι Andromedae
Iota Andromedae
Iota Andromedae is a star in the constellation Andromeda.Iota Andromedae is a blue-white B-type main sequence dwarf with an apparent magnitude of +4.29...

. Consequently, π2 Cygni itself is known as

Structure

Pi² Cygni is a spectroscopic binary
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...

 with its main component being a Class B3
Stellar classification
In astronomy, stellar classification is a classification of stars based on their spectral characteristics. The spectral class of a star is a designated class of a star describing the ionization of its chromosphere, what atomic excitations are most prominent in the light, giving an objective measure...

 blue giant
Blue giant
In astronomy, a blue giant is a star with a spectral type of O or B and a luminosity class of III...

 star with an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...

 of +4.23 and a stellar luminosity
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...

 nearly 2,200 times that of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

. This binary star system is approximately 1156 light years
Light Years
Light Years is the seventh studio album by Australian recording artist Kylie Minogue. It was released on 25 September 2000 by Parlophone and Mushroom Records. The album's style was indicative of her return to "mainstream pop dance tunes"....

 from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

.
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