Nu Scorpii (ν Scorpii, abbreviated Nu Sco, ν Sco) is a

multiple star system A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. It may sometimes be used to refer to a single star. A large group of stars bound by gravitation is generally called a ''st ...

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 ...

Scorpius Scorpius is a zodiac constellation located in the Southern celestial hemisphere, where it sits near the center of the Milky Way, between Libra to the west and Sagittarius to the east. Scorpius is an ancient constellation whose recognition pred ...

. It is most likely a septuple star system, consisting of two close groups (designated Nu Scorpii AB and CD) that are separated by 41

arcseconds A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of a degree. Since one degree is of a turn, or complete rotation, one arcminute is of a tu ...

. 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 approximately 470

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

s from the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

. The component Nu Scorpii Aa is formally named Jabbah . (Contrast the similar-sounding

Dschubba Delta Scorpii ( Latinised from δ Scorpii, abbreviated Delta Sco, δ Sco) is a binary star (the presence of a third star in the system is being debated) in the constellation of Scorpius. The primary star is named Dschubba . Observation ...

, Delta Scorpii.)

Location

Nu Scorpii is the system that causes the

reflection nebula In astronomy, reflection nebulae are interstellar cloud, clouds of Cosmic dust, interstellar dust which might reflect the light of a nearby star or stars. The energy from the nearby stars is insufficient to Ionization, ionize the gas of the nebu ...

cataloged as IC 4592 and known as the Blue Horsehead nebula. Reflection nebulae are actually made up of very fine dust that normally appears dark but can look quite blue when reflecting the light of energetic nearby stars. Since it is near the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

, Nu Scorpii can be

occulted An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks f ...

by the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

and, very rarely, by

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

s. Mercury occulted it on 14 December 1821, but will not occult it again until 2 December 2031. The last occultation by

Venus Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

took place on 27 December 1852 and the next will take place on 30 December 2095. On 29 July 1808 there was an occultation by

Neptune Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

Nomenclature

''ν Scorpii'' ( Latinised to ''Nu Scorpii'') is the system's

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 ...

. The designations of its two constituent groups as ''Nu Scorpii AB'' and ''CD''; of the component ''Nu Scorpii Aa'', and of other components similarly lettered, derive from the convention used by the Washington Multiplicity Catalog (WMC) for

s, and adopted by the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

(IAU).

Nu Scorpii bore the traditional name ''Jabbah'', possibly from the

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

''Iklīl al Jabhah'' (إكليل الجبهة 'the crown of the forehead'). In 2016, the IAU 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 catalog 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 ''Jabbah'' for the component Nu Scorpii Aa on 30 June 2017 and it is now so included in the List of IAU-approved Star Names. In

Chinese astronomy Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The Ancient China, ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categori ...

, Nu Scorpii is called 鍵閉,

Pinyin Hanyu Pinyin, or simply pinyin, officially the Chinese Phonetic Alphabet, is the most common romanization system for Standard Chinese. ''Hanyu'' () literally means 'Han Chinese, Han language'—that is, the Chinese language—while ''pinyin' ...

: Jiànbì, meaning ''Door Bolt'', because it is marking itself and standing alone in the ''Door Bolt'' asterism,

Room In a building or a ship, a room is any enclosed space within a number of walls to which entry is possible only via a door or other dividing structure. The entrance connects it to either a passageway, another room, or the outdoors. The space is ...

mansion (see :

Chinese constellations Traditional Chinese astronomy has a system of dividing the celestial sphere into asterisms or constellations, known as "officials" ( Chinese ''xīng guān''). The Chinese asterisms are generally smaller than the constellations of Hellenisti ...

). 鍵閉 (Jiànbì), westernized into ''Keen Pi'', but that name (meaning "the Two Parts of a Lock") was ascribed to the pair

Lambda Scorpii Lambda Scorpii is a triple star system and the second-brightest object in the constellation of Scorpius. It is formally named Shaula; ''Lambda Scorpii'' is its Bayer designation, which is Latinised from λ Scorpii and abbreviated Lam ...

(Shaula) and

Upsilon Scorpii Upsilon Scorpii (υ Scorpii, abbreviated Upsilon Sco, υ Sco), formally named Lesath , is a star located in the "stinger" of the southern zodiac constellation of Scorpius, the scorpion. Based on parallax measurements obtained during the H ...

(Lesath) by R.H. Allen.

Multiplicity

Hierarchy of orbits in the ν Scorpii system Construction_of_Nu_Scorpii

Nu Scorpii is a septuple star system. It is one of only two such known systems, the other being

AR Cassiopeiae AR Cassiopeiae (AR Cas) is a variable star in the constellation of Cassiopeia (constellation), Cassiopeia. It is thought to be a member of a multiple star system, septuple star system, one of only two known star systems with a multipl ...

. Higher-multiplicity star systems are uncommon because they are less stable than their simpler counterparts, and often decay into smaller systems. Nu Scorpii is split into two groups, Nu Scorpii AB and Nu Scorpii CD. Nu Scorpii CD is located 41

away from Nu Scorpii A, and is also known as HR 6026.

Nu Scorpii A

Nu Scorpii A is the brightest member of the system. It has an

apparent magnitude Apparent magnitude () is a measure of the Irradiance, 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 (astronomy), ...

from 4.35, meaning that it can be seen with the naked eye. However, Nu Scorpii AB and CD cannot be resolved using the naked eye, but it can be resolved using a telescope. Nu Scorpii A is itself a

triple star system A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. It may sometimes be used to refer to a single star. A large group of stars bound by gravitation is generally called a ''st ...

. The main component of Nu Scorpii A is known as Nu Scorpii Aab, and it is a single-lined

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 ...

. Its components cannot be resolved but the stars' movements cause periodic Doppler shifts in their spectra. "Single-lined" means that light from only one of the stars can be detected. The pair has an

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 5.5521 days 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-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.11, and an estimated separation of about 1.057 milliarcseconds. The brighter component, Nu Scorpii Aa, has a

spectral type 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 B3V implying a B-type

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 ...

star. The fainter component, Nu Scorpii Ab, is thought to have an apparent magnitude of 6.90. Nu Scorpii Ac is the third component of the Nu Scorpii A subsystem. 63 milliarcseconds away, it has an apparent magnitude of 6.62.

Nu Scorpii B

Nu Scorpii B is part of the Nu Scorpii AB sub-system and orbits Nu Scorpii A. It has an apparent magnitude of 5.40, but its spectral type is unknown. Nu Scorpii A and B are separated by 1.305 arcseconds; this translates to an orbital period of over 452

year A year is a unit of time based on how long it takes the Earth to orbit the Sun. In scientific use, the tropical year (approximately 365 Synodic day, solar days, 5 hours, 48 minutes, 45 seconds) and the sidereal year (about 20 minutes longer) ...

s, so no

orbital motion In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an obj ...

has been detected.

Nu Scorpii CD

Nu Scorpii CD is also a triple star system. The primary component of the system, Nu Scorpii C, is a late

B-type giant In astronomy, a blue giant is a hot star with a luminosity class of III (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 variety of s ...

with a spectral type of B9III. With an apparent magnitude of 6.90, it outshines its fainter companion, Nu Scorpii D, which only has an apparent magnitude of 7.39. The two are separated by about 2 arcseconds. Nu Scorpii D, with an apparent magnitude of 7.39, is the faintest component of the Nu Scorpii system. It is one of a class of

chemically peculiar star In astrophysics, chemically peculiar stars (CP stars) are stars with distinctly unusual Metallicity, metal abundances, at least in their surface layers. Classification Chemically peculiar stars are common among hot main-sequence (hydrogen-burning) ...

s known as Ap/Bp stars; in particular, it has strong

silicon Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a membe ...

emission lines. It too is likely also another spectroscopic binary: Nu Scorpii Da is another B9III-type star, similar to Nu Scorpii C, but very little is known about Nu Scorpii Db.

References

External links

* {{Stars of Scorpius Scorpii, Nu B-type main-sequence stars B-type subgiants 7 Scorpius Spectroscopic binaries

Jabbah Nu Scorpii (ν Scorpii, abbreviated Nu Sco, ν Sco) is a multiple star system in the constellation of Scorpius. It is most likely a septuple star system, consisting of two close groups (designated Nu Scorpii AB and CD) that are separat ...

Scorpii, 14 079374 6026 7 145501 2 Durchmusterung objects