Nu Andromedae is a

binary star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

system in the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

Andromeda. Its

Bayer designation A Bayer designation is a stellar designation in which a specific star is identified by a Greek alphabet, Greek or Latin letter followed by the genitive case, genitive form of its parent constellation's Latin name. The original list of Bayer design ...

is Latinized from ν Andromedae, and abbreviated Nu And or ν And, respectively. The system has an

apparent visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

of 4.5, which is bright enough to be seen with the

naked eye Naked eye, also called bare eye or unaided eye, is the practice of engaging in visual perception unaided by a magnification, magnifying, Optical telescope#Light-gathering power, light-collecting optical instrument, such as a telescope or microsc ...

. Based on

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

measurements, it is located at a distance of approximately from

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

. The pair are drifting closer with a heliocentric

radial velocity The radial velocity or line-of-sight velocity of a target with respect to an observer is the rate of change of the vector displacement between the two points. It is formulated as the vector projection of the target-observer relative velocity ...

of –24 km/s. Situated just over a degree to the west of this star is the

Andromeda Galaxy The Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a Galaxy#Isophotal diameter, D25 isop ...

. Nu Andromedae is close

spectroscopic binary A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

system with a period of 4.2828 days and a nearly circular orbit. The primary component is a

B-type main sequence star A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars ...

with a

stellar classification In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction gratin ...

of B5 V. The fainter secondary has a classification of F8 V, which makes it an

F-type main sequence star An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F and luminosity class V. These stars have from 1.0 to 1.4 times the mass of the Sun and surface temperatures between 6,000 and 7,600 K.Tables ...

. The pair is about 63 million years old. The pair have a

peculiar velocity Peculiar motion or peculiar velocity refers to the velocity of an object relative to a ''rest frame''—usually a frame in which the average velocity of some objects is zero. Galactic astronomy In galactic astronomy, peculiar motion refers to t ...

of relative to neighboring stars, which doesn't qualify it to be a

runaway star In astronomy, stellar kinematics is the observational study or measurement of the kinematics or motions of stars through space. Stellar kinematics encompasses the measurement of stellar velocities in the Milky Way and its satellites as well as ...

system but does suggest it escaped its

star cluster A star cluster is a group of stars held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters, tight groups of ten thousand to millions of old stars which are gravitationally bound; and open cluster ...

of origin. The trajectory indicates it may have left the NGC 6405 cluster some 25 million years ago.

Naming

Chinese Chinese may refer to: * Something related to China * Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity **Han Chinese, East Asian ethnic group native to China. **'' Zhonghua minzu'', the supra-ethnic ...

, (), meaning ''

Legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...

(asterism)'', refers to an asterism consisting of ν Andromedae, η Andromedae,

65 Piscium This is the list of notable stars in the constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythologi ...

, ζ Andromedae, ε Andromedae,

δ Andromedae Delta Andromedae is a triple star system in the northern constellation of Andromeda (constellation), Andromeda. Its identifier is a Bayer designation that is Romanization of Greek, Latinized from δ Andromedae, and abbreviated Delta ...

, π Andromedae,

μ Andromedae Mu Andromedae is a binary star system in the northern constellation of Andromeda (constellation), Andromeda. Its Bayer designation is Romanization of Greek, Latinized from μ Andromedae, and abbreviated Mu And or μ And, r ...

, β Andromedae,

σ Piscium Sigma Piscium (Sigma Psc, σ Piscium, σ Psc) is a binary star in the zodiac constellation of Pisces. It has an apparent magnitude of +5.50, meaning it is barely visible to the naked eye, according to the Bortle scale ...

τ Piscium Tau Piscium (τ Piscium) is an orange-hued star in the zodiac constellation of Pisces. With an apparent visual magnitude of +4.52, it is a dim star but visible to the naked eye. Based upon an annual parallax shift of 19.32 ...

, 91 Piscium,

υ Piscium Upsilon Piscium is a solitary, white-hued star in the zodiac constellation of Pisces. It is faintly visible to the naked eye, having an apparent visual magnitude of +4.75. Based upon an annual parallax shift of as seen from Earth, it is ...

φ Piscium Phi Piscium, Latinized from φ Piscium, is a quadruple star system approximately 380 light years away in the constellation Pisces. It consists of Phi Piscium A, with a spectral type of K0III, and Phi Piscium B. Phi Piscium A posse ...

, χ Piscium and ψ¹ Piscium. Consequently, the

Chinese name Chinese may refer to: * Something related to China * Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity **Han Chinese, East Asian ethnic group native to China. **'' Zhonghua minzu'', the supra-ethni ...

for ν Andromedae itself is (, .)AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 5 月 19 日

References

External links

* {{DEFAULTSORT:Nu Andromedae B-type main-sequence stars F-type main-sequence stars Spectroscopic binaries Andromeda (constellation) Andromedae, Nu 0226 Durchmusterung objects Andromedae, 35 004727 003881