Chi Andromedae ( Andromedae, And) is the

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1,564 stars. T ...

for a

star A star is an astronomical object comprising a luminous spheroid of plasma held together by its gravity. The nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night, but their immense distances from Earth make ...

in the northern constellation of Andromeda. It has an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's lig ...

of +5.01, which is relatively faint for a naked-eye star. Based upon

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight and is measured by the angle or semi-angle of inclination between those two lines. Due to foreshortening, nearby object ...

measurements made during the

Gaia In Greek mythology, Gaia (; from Ancient Greek , a poetical form of , 'land' or 'earth'),, , . also spelled Gaea , is the personification of the Earth and one of the Greek primordial deities. Gaia is the ancestral mother—sometimes parthe ...

mission, Chi Andromedae is located around from Earth. χ Andromedae is a member of (), meaning ''

Heaven's Great General ''Teen Ta Tseang Keun'' () or ''Tëen ta tsëang keun'' meaning "Heaven's Great General",Allen (1963): p.37. was a Chinese constellation () in the region of '' Lóu'' (). It contained stars of the western constellations Andromeda and Triangulum. ...

'', together with

γ Andromedae Gamma Andromedae, Latinized from γ Andromedae, is the third-brightest point of light in the northern constellation of Andromeda. It is a multiple star system approximately 350 light-years from Earth. The system is drifting closer ...

φ Persei Phi Persei (Phi Per, φ Persei, φ Per) is a Stellar classification, Class B2Vpe fourth-magnitude star in the constellation Perseus (constellation), Perseus, location about 720 light-years from Earth. System Phi Persei i ...

, 51 Andromedae,

49 Andromedae 49 Andromedae (abbreviated 49 And) is a star in the constellation Andromeda. ''49 Andromedae'' is the Flamsteed designation though it also bears the Bayer designation A Andromedae. It is visible to the naked eye under good viewing c ...

, θ Andromedae,

τ Andromedae Tau Andromedae, Latinized from τ Andromedae, is the Bayer designation for a single star in the northern constellation of Andromeda. It has an apparent visual magnitude of +4.94, which is bright enough to be viewed from dark suburban ...

, 56 Andromedae,

β Trianguli Beta Trianguli (Beta Tri, β Trianguli, β Tri) is the Bayer designation for a binary star system in the constellation Triangulum, located about 127 light years from Earth. Although the apparent magnitude is only ...

γ Trianguli Gamma Trianguli (Gamma Tri, γ Trianguli, γ Tri) is a star in the constellation Triangulum located approximately 112 light years from Earth. It has an apparent magnitude of +4.01 and forms an optical (line-of-sight) triple ...

and

δ Trianguli Delta Trianguli, Romanization of Greek, Latinized from Delta Tri, is a spectroscopic binary star system approximately away in the constellation of Triangulum. The primary star is a Yellow dwarf star, yellow dwarf, while the seconda ...

. Consequently, the

Chinese name Chinese names or Chinese personal names are names used by individuals from Greater China and other parts of the Chinese-speaking world throughout East and Southeast Asia (ESEA). In addition, many names used in Japan, Korea and Vietnam are oft ...

for χ Andromedae itself is (, en, the Fifth Star of Heaven's Great General.)AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 10 日
/ref> This is most likely a spectroscopic binary system with an estimated

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 20.8 years and an

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off- center, in geometry * Eccentricity (graph theory) of a ...

of 0.37. The primary component has a

stellar classification In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting t ...

of G8 III, which indicates it is a

giant star A giant star is a star with substantially larger radius and luminosity than a main-sequence (or ''dwarf'') star of the same surface temperature.Giant star, entry in ''Astronomy Encyclopedia'', ed. Patrick Moore, New York: Oxford University Press ...

that has exhausted the supply of hydrogen at its core and

evolved Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation te ...

away from the

main sequence In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

. The outer envelope has expanded to about nine times the radius of the Sun and it is radiating 47 times the luminosity of the Sun at an

effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature ...

of 5,070 K. This heat gives the star the yellow-hued glow of a

G-type star A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective tempe ...

. It appears to be rotating very slowly with no measurable

projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surface. The rotation of a star produces an equatorial bulge ...

. The secondary component seems to be a main-sequence star of the spectral class G or K.

References

External links

Simbad

Image Chi Andromedae
{{DEFAULTSORT:Chi Andromedae Andromedae, Chi Andromedae, 52 010072 Andromeda (constellation) G-type giants 007719 0469 BD+43 0343 Spectroscopic binaries