Upsilon Piscium is a solitary, white-hued

star A star is a luminous spheroid of plasma (physics), plasma held together by Self-gravitation, self-gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sk ...

in the

zodiac The zodiac is a belt-shaped region of the sky that extends approximately 8° north and south celestial latitude of the ecliptic – the apparent path of the Sun across the celestial sphere over the course of the year. Within this zodiac ...

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 ...

Pisces Pisces may refer to: *Pisces (astrology), an astrological sign Astronomy *Pisces (constellation), a constellation ** Pisces Overdensity, an overdensity of stars in the Milky Way's halo that is situated in the Pisces constellation ** Pisces II, a ...

. It is faintly visible to the naked eye, having 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 +4.75. Based upon an annual parallax shift of as seen from Earth, it is located about 308

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s from the Sun. The star is drifting further away 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 +6 km/s. This is an ordinary

A-type main sequence star An A-type main-sequence star (A) or A dwarf star is a main-sequence (hydrogen burning) star of spectral type A and luminosity class (five). These stars have spectra defined by strong hydrogen Balmer absorption lines. They measure between 1.7 ...

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 A3 V. It is 461 million years old – about 98% of the way through its

main sequence In astronomy, the main sequence is a classification of stars which appear on plots of stellar color index, color versus absolute magnitude, brightness as a continuous and distinctive band. Stars on this band are known as main-sequence stars or d ...

lifetime – and is spinning with a

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 bu ...

of 91 km/s. The star has 2.8 times the

mass of the Sun The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies a ...

, about 2.2 times the

Sun's radius Solar radius is a unit of distance used to express the size of objects in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: 1\,R_ = 6.957\ti ...

, and is radiating 117 times the

Sun's luminosity The solar luminosity () is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal s ...

from its

photosphere The photosphere is a star's outer shell from which light is radiated. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will esc ...

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 9183 K.

Naming

υ Piscium is the

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 ...

for this star, which is Latinized as Upsilon Piscium. It has the

Flamsteed designation A Flamsteed designation is a combination of a number and constellation name that uniquely identifies most naked eye stars in the 88 modern constellations, modern constellations visible from southern England. They are named after John Flamsteed, au ...

90 Piscium. In Chinese, (), 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 composed of υ Piscium, 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, ν 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,

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

References

{{DEFAULTSORT:Upsilon Piscium A-type main-sequence stars Pisces (constellation) Piscium, Upsilon Durchmusterung objects Piscium, 090 007964 006193 0383