Gamma Corvi (γ Corvi, abbreviated Gamma Crv, γ Crv) is a

binary star A binary star 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 using a telescope as separate stars, in ...

and the brightest star in the southern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellation ...

Corvus ''Corvus'' is a widely distributed genus of medium-sized to large birds in the family Corvidae. It includes species commonly known as crows, ravens and rooks. The species commonly encountered in Europe are the carrion crow, the hooded crow ...

, having 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 2.59. The system's two components are designated Gamma Corvi A (officially named Gienah , traditionally the name of the system)) and Gamma Corvi B, whose magnitude is 9.7 and which is 1.1 arcseconds away from Gamma Corvi

The distance to this system has been measured directly using the stellar parallax, parallax technique, yielding an estimated 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

''γ Corvi'' ( Latinised to ''Gamma Corvi'') is the system'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 ...

. The designation of the components – ''Gamma Corvi A'' and ''B'' – derives from the convention used by the Washington Multiplicity Catalog (WMC) for

multiple star system A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a ''star cluster'' or ''galaxy'', although, broadly speaking ...

s, and adopted by the

International Astronomical Union The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...

(IAU). Gamma Corvi bore the traditional name of ''Gienah'' derived from

Arabic Arabic (, ' ; , ' or ) is a 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. E.Watson; Walter ...

, from

Ulugh Beg Mīrzā Muhammad Tāraghay bin Shāhrukh ( chg, میرزا محمد طارق بن شاہ رخ, fa, میرزا محمد تراغای بن شاہ رخ), better known as Ulugh Beg () (22 March 1394 – 27 October 1449), was a Timurid sultan, as ...

's الجناح الغراب اليمن ''al-janāħ al-ghirāb al-yaman'', meaning "the right wing of the crow", although on modern charts it marks the left wing. The star Epsilon Cygni also bore this traditional name and Gamma Corvi was referred to as ''Gienah Corvi'' or ''Gienah Ghurab'' to distinguish it from this star in Cygnus. In 2016, the

organized a

Working Group on Star Names The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education ...

(WGSN) to catalogue and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name ''Gienah'' for the component ''Gamma Corvi A'' on 6 November 2016 and ''Aljanah'' for ''Epsilon Cygni Aa'' on 30 June 2017. They are both now so included in the List of IAU-approved Star Names. ''Al-janāħ al-ghirāb al-yaman'' or ''Djenah al Ghyrab al Eymen'' appeared in the catalog of stars in the ''Calendarium of Al Achsasi Al Mouakket'', which was translated into

Latin Latin (, or , ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through ...

as ''Dextra ala Corvi''. In Chinese, (), meaning '' Chariot (asterism)'', refers to an asterism consisting of Gamma Corvi,

Epsilon Corvi Epsilon Corvi (ε Crv, ε Corvi) is a star in the southern constellation of Corvus. It has the traditional name Minkar , from Arabic منقار ''minqar'' meaning "beak f the crow The apparent visual magnitude is +3.0 and it is located ...

, Delta Corvi and

Beta Corvi Beta Corvi or β Corvi, officially named Kraz (), is the second-brightest star in the southern constellation of Corvus with an apparent visual magnitude of 2.647. Based on parallax measurements obtained during the Hipparcos mis ...

. Consequently, Gamma Corvi itself is known as (, en, the First Star of Chariot).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

Gamma Corvi A 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 ...

with 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 the ...

of B8 III and has approximately 4.2 times the

mass of the Sun 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 ...

. It has a blue-white hue. The

spectrum A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...

of this star displays an anomalously higher than normal abundance of the elements mercury and

manganese Manganese is a chemical element with the Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of ...

, making this a

Mercury-manganese star A mercury-manganese star (also HgMn star) is a type of chemically peculiar star with a prominent spectral line at 398.4 nm, due to absorption from ionized mercury. These stars are of spectral type B8, B9, or A0, corresponding to surface temper ...

. However, there are other elements that show large over or under abundances. This chemical peculiarity in an otherwise stable stellar atmosphere is most likely caused by separation of the elements through diffusion and gravitational settling. It has a confirmed stellar companion with a mass of about 0.8 times the Sun's, which may be orbiting at a separation of around 50 AU over a 158-year

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

. The photometry for Gamma Corvi B suggests a stellar classification in the range K5–M5 V.

References

{{Stars of Corvus Corvi, Gamma B-type giants Corvus (constellation) Gienah Binary stars Corvi, 04 059803 106625 4662 Durchmusterung objects