Xi Persei (ξ Persei, abbreviated Xi Per, ξ Per), known also as Menkib , is a

star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...

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 origins of the e ...

Perseus In Greek mythology, Perseus (Help:IPA/English, /ˈpɜːrsiəs, -sjuːs/; Greek language, Greek: Περσεύς, Romanization of Greek, translit. Perseús) is the legendary founder of Mycenae and of the Perseid dynasty. He was, alongside Cadmus ...

. 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 objects ...

measurements taken during the

Hipparcos ''Hipparcos'' was a scientific satellite of the European Space Agency (ESA), launched in 1989 and operated until 1993. It was the first space experiment devoted to precision astrometry, the accurate measurement of the positions of celestial obj ...

mission, it is approximately 1,200

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

Nomenclature

''ξ Persei'' ( Latinised to ''Xi Persei'') is the star's

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. ...

. It bore the traditional name ''Menkib'', ''Menchib'', ''Menkhib'' or ''Al Mankib'', from ''Mankib al Thurayya'' (

Arabic Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...

for "shoulder" f the Pleiades">Pleiades.html" ;"title="f the Pleiades">f the Pleiades. In 2016, the International Astronomical Union (IAU) organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name ''Menkib'' for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names. In

Chinese Chinese can refer to: * Something related to China * Chinese people, people of Chinese nationality, citizenship, and/or ethnicity **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of va ...

, (), meaning '' Rolled Tongue'', refers to an asterism consisting of Xi Persei,

Nu Persei ν Persei, Latinized as Nu Persei, is a single star and a suspected variable in the northern constellation of Perseus. It has a yellow-white hue and is visible to the naked eye with an apparent visual magnitude of 3.80. This object is lo ...

Epsilon Persei Epsilon Persei, Latinized from ε Persei, is a multiple star system in the northern constellation of Perseus. It has a combined apparent visual magnitude of +2.88, which is bright enough to be viewed with the naked eye. Based upon ...

Zeta Persei Zeta Persei (ζ Per, ζ Persei) is a star in the northern constellation of Perseus. With an apparent visual magnitude of 2.9, it can be readily seen with the naked eye. Parallax measurements place it at a distance of about from Earth. De ...

Omicron Persei Omicron Persei (ο Persei, abbreviated Omicron Per, ο Per) is a triple star system in the constellation of Perseus. From parallax measurements taken during the Hipparcos mission it is approximately 1,100 light-years (330 parsecs) from t ...

and

40 Persei 40 Persei is a wide binary star system in the northern constellation of Perseus. It has the Bayer designation ο Persei, while ''40 Persei'' is the Flamsteed designation. The system is visible to the naked eye as a faint, blue-white hued ...

. Consequently, the Chinese name for Xi Persei itself is (, "the Third Star of Rolled Tongue").香港太空館 - 研究資源 - 亮星中英對照表
, Hong Kong Space Museum. Accessed on line November 23, 2010.

Properties

Xi Persei has an

apparent 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 li ...

of +4.06 and is classified as a

blue giant In astronomy, a blue giant is a hot star with a luminosity class of III (giant star, giant) or II (bright giant). In the standard Hertzsprung–Russell diagram, these stars lie above and to the right of the main sequence. The term applies to a ...

(

spectral class 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 the ...

O7.5III). It is intrinsically 12,700 times brighter than the

with

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

−5.5 in the V band. If the ultraviolet light and light from other wavelengths that emanates from Menkib is included, its total bolometric luminosity is 263,000 times that of the Sun. The star has a mass of some 30

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

es and a surface temperature of 35,000

kelvin The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and phys ...

s, making it one of the hottest stars that can be seen with the naked eye. The fluorescence of the

California Nebula The California Nebula ( NGC 1499/ Sh2-220) is an emission nebula located in the constellation Perseus. Its name comes from its resemblance to the outline of the US State of California in long exposure photographs. It is almost 2.5° long on the ...

(NGC 1499) is due to this star's prodigious radiation. It is a member of the Perseus OB2 association of co-moving stars, but may 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 t ...

since it is now separated by 200 pc from the association's center and has an unusually high

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

References

External links

* {{DEFAULTSORT:Xi Persei O-type giants Emission-line stars Runaway stars Perseus (constellation) Persei, Xi BD+35 0775 Persei, 46 024912 018614

1228 Year 1228 ( MCCXXVIII) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. Events By place Sixth Crusade * Summer – Emperor Frederick II sails from Brindisi with a expeditionary f ...

Menkib