, - bgcolor="#FFFAFA"
, Note (category: variability): , , H and K emission vary.
Arcturus is the brightest
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
northern
Northern may refer to the following:
Geography
* North, a point in direction
* Northern Europe, the northern part or region of Europe
* Northern Highland, a region of Wisconsin, United States
* Northern Province, Sri Lanka
* Northern Range, a ra ...
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 ...
of
Boötes
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from la, Boōtēs, which comes from grc-gre, Βοώτης, Boṓtēs ...
. With 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 −0.05,
[ it is the third-brightest of the individual stars in the ]night sky
The night sky is the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon.
Natural light sources in a night sky include ...
, and the brightest in the northern celestial hemisphere. The name Arcturus originated from ancient Greece
Ancient Greece ( el, Ἑλλάς, Hellás) was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity ( AD 600), that comprised a loose collection of cult ...
; it was then cataloged as α Boötis by Johann Bayer
Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain, Lower Bavaria, in 1572. At twenty, in 1592 he began his study of philosophy and law at the University of Ingolstadt, a ...
in 1603, which is Latinized to Alpha Boötis. Arcturus forms one corner of the Spring Triangle
The Spring Triangle is an astronomical asterism involving an imaginary triangle drawn upon the celestial sphere, with its defining vertices at Arcturus, Spica, and Regulus. This triangle connects the constellations of Boötes, Virgo, and Leo. ...
asterism.
Located relatively close at 36.7 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 ...
, Arcturus is a single[ ]red giant
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses ()) in a late phase of stellar evolution. The outer atmosphere is inflated and tenuous, making the radius large and the surface temperature around or ...
of spectral type
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 grati ...
K1.5III—an aging star around 7.1 billion years old that has used up its core
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (manufacturing), used in casting and molding
* Core (optical fiber), the signal-carrying portion of an optical fiber
* Core, the central ...
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
and evolved
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...
off the main sequence
In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...
. It is about the same mass as the Sun, but has expanded to 25 times its size and is around 170 times as luminous. Its diameter is 35 million kilometres. Thus far no companion has been detected.
Nomenclature
The traditional name ''Arcturus'' is Latinised from the ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
Ἀρκτοῦρος (''Arktouros'') and means "Guardian of the Bear", ultimately from ἄρκτος (''arktos''), "bear" and οὖρος (''ouros''), "watcher, guardian".
The designation of Arcturus as ''α Boötis'' ( Latinised to ''Alpha Boötis'') was made by Johann Bayer
Johann Bayer (1572 – 7 March 1625) was a German lawyer and uranographer (celestial cartographer). He was born in Rain, Lower Bavaria, in 1572. At twenty, in 1592 he began his study of philosophy and law at the University of Ingolstadt, a ...
in 1603. In 2016, 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 ...
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's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included ''Arcturus'' for α Boötis.
Observation
With 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 −0.05, Arcturus is the brightest star in the northern celestial hemisphere and the fourth-brightest star in the night sky,[ after ]Sirius
Sirius is the list of brightest stars, brightest star in the night sky. Its name is derived from the Ancient Greek language, Greek word , or , meaning 'glowing' or 'scorching'. The star is designated α Canis Majoris, Latinisation ...
(−1.46 apparent magnitude), Canopus
Canopus is the brightest star in the southern constellation of Carina (constellation), Carina and the list of brightest stars, second-brightest star in the night sky. It is also Bayer designation, designated α Carinae, which is Lat ...
(−0.72) and α Centauri
Alpha Centauri (Latinisation of names, Latinized from α Centauri and often abbreviated Alpha Cen or α Cen) is a Star System, triple star system in the constellation of Centaurus (constellation), Centaurus. It consists of 3 stars: ...
(combined magnitude of −0.27). However, α Centauri AB 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 wh ...
, whose components are both fainter than Arcturus. This makes Arcturus the third-brightest individual star, just ahead of α Centauri A (officially named ''Rigil Kentaurus''), whose apparent magnitude .[ The French mathematician and astronomer Jean-Baptiste Morin observed Arcturus in the daytime with a telescope in 1635, a first for any star other than 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 ...
and supernova
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...
e. Arcturus has been seen at or just before sunset with the naked eye.[
Arcturus is visible from both of ]Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
's hemispheres as it is located 19° north of the celestial equator
The celestial equator is the great circle of the imaginary celestial sphere on the same plane as the equator of Earth. This plane of reference bases the equatorial coordinate system. In other words, the celestial equator is an abstract projectio ...
. The star culminates at midnight on 27 April, and at 9 p.m. on June 10 being visible during the late northern spring or the southern autumn. From the northern hemisphere
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the solar system as Earth's Nort ...
, an easy way to find Arcturus is to follow the arc of the handle of the Big Dipper
The Big Dipper ( US, Canada) or the Plough ( UK, Ireland) is a large asterism consisting of seven bright stars of the constellation Ursa Major; six of them are of second magnitude and one, Megrez (δ), of third magnitude. Four define a "bowl" ...
(or Plough). By continuing in this path, one can find Spica
Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analys ...
, "Arc to Arcturus, then spike (or speed on) to Spica".[ Together with the bright stars ]Spica
Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analys ...
and Denebola
Denebola is the second-brightest star in the zodiac constellation of Leo.The two components of the γ Leonis double star, which are unresolved to the naked eye, have a combined magnitude brighter than it. It has the Bayer designatio ...
(or Regulus
Regulus is the brightest object in the constellation Leo and one of the brightest stars in the night sky. It has the Bayer designation designated α Leonis, which is Latinized to Alpha Leonis, and abbreviated Alpha Leo or α Leo. Re ...
, depending on the source), Arcturus is part of the Spring Triangle
The Spring Triangle is an astronomical asterism involving an imaginary triangle drawn upon the celestial sphere, with its defining vertices at Arcturus, Spica, and Regulus. This triangle connects the constellations of Boötes, Virgo, and Leo. ...
asterism. With Cor Caroli
Cor Caroli is a binary star designated Alpha Canum Venaticorum or α Canum Venaticorum. The International Astronomical Union uses the name "Cor Caroli" specifically for the brighter star of the binary. Alpha Canum Venaticorum is the brig ...
, these four stars form the Great Diamond
The Great Diamond is an asterism. Astronomy popularizer Hans A. Rey called it the Virgin's Diamond. (In fact, long before mentioned in R. Hinckley-Allen's "Star-Names and Their Meanings", 1899, p.259, as "the celebrated Diamond of Virgo"; see ...
asterism.
Ptolemy described Arcturus as ''subrufa'' ("slightly red"): it has a B-V color index of +1.23, roughly midway between Pollux (B-V +1.00) and Aldebaran
Aldebaran (Arabic: “The Follower”, "الدبران") is the brightest star in the zodiac constellation of Taurus. It has the Bayer designation α Tauri, which is Latinized to Alpha Tauri and abbreviated Alpha Tau or α Tau. Aldebar ...
(B-V +1.54).[
]η Boötis
Eta (uppercase , lowercase ; grc, ἦτα ''ē̂ta'' or ell, ήτα ''ita'' ) is the seventh letter of the Greek alphabet, representing the close front unrounded vowel . Originally denoting the voiceless glottal fricative in most dialects, ...
, or Muphrid, is only 3.3 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 distant from Arcturus, and would have a visual magnitude −2.5, about as bright as Mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Merc ...
from Earth, whereas an observer on the former system would find Arcturus as bright as Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
as seen from Earth.[
In 1984, the 90 cm (36-inch) reflecting Yapp telescope at ]Herstmonceux
Herstmonceux ( , ; ) is a village and civil parish in the Wealden District of East Sussex, England, which includes Herstmonceux Castle.
The Herstmonceux Medieval Festival is held annually in August.
History
The name comes from Anglo-Saxon ...
was tested with an echelle spectrograph
An echelle grating (from French ''échelle'', meaning "ladder") is a type of diffraction grating characterised by a relatively low groove density, but a groove shape which is optimized for use at high incidence angles and therefore in high diffract ...
from Queen's University Belfast
, mottoeng = For so much, what shall we give back?
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and a CCD camera. Observations of the stars Arcturus and Deneb
Deneb () is a first-magnitude star in the constellation of Cygnus, the swan. Deneb is one of the vertices of the asterism known as the Summer Triangle and the "head" of the Northern Cross. It is the brightest star in Cygnus and the ...
(Alpha Cygni) were conducted in the summer of 1984.[
]
Physical characteristics
Based upon an annual 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 ...
shift of 88.83 milliarcseconds
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...
as measured by 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 ...
satellite, Arcturus is from the Sun. The parallax margin of error
The margin of error is a statistic expressing the amount of random sampling error in the results of a survey. The larger the margin of error, the less confidence one should have that a poll result would reflect the result of a census of the ent ...
is 0.54 milliarcseconds, translating to a distance margin of error of ±. Because of its proximity, Arcturus has a high proper motion
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...
, two arcseconds
A minute of arc, arcminute (arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of angular measurement equal to of one degree. Since one degree is of a turn (or complete rotation), one minute of arc is of a turn. The na ...
a year, greater than any first magnitude star
First-magnitude stars are the brightest stars in the night sky, with apparent magnitudes lower (i.e. brighter) than +1.50. Hipparchus, in the 1st century B.C., introduced the magnitude scale. He allocated first magnitude to the 20 brightest stars ...
other than α Centauri.
Arcturus is moving rapidly () relative to the Sun, and is now almost at its closest point to the Sun. Closest approach will happen in about 4,000 years, when the star will be a few hundredths of a light-year closer to Earth than it is today. (In antiquity, Arcturus was closer to the centre of the constellation.[) Arcturus is thought to be an ]old-disk star
The thick disk is one of the structural components of about 2/3 of all disk galaxies, including the Milky Way. It was discovered first in external edge-on galaxies. Soon after, it was proposed as a unique galactic structure in the Milky Way, diff ...
,[ and appears to be moving with a group of 52 other such stars, known as the ]Arcturus stream In astronomy, the Arcturus moving group or Arcturus stream is a moving group or stellar stream, discovered by Olin J. Eggen (1971), comprising 53 stars moving at 275,000 miles per hour, which includes the nearby bright star Arcturus. It comprises m ...
.[
With an ]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 ...
of −0.30, Arcturus is, together with Vega
Vega is the brightest star in the northern constellation of Lyra. It has the Bayer designation α Lyrae, which is Latinised to Alpha Lyrae and abbreviated Alpha Lyr or α Lyr. This star is relatively close at only from the Sun, an ...
and Sirius, one of the most luminous stars in the Sun's neighborhood. It is about 110 times brighter than the Sun in visible light wavelengths, but this underestimates its strength as much of the light it gives off is in the infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
; total (bolometric
A bolometer is a device for measuring radiant heat by means of a material having a temperature-dependent electrical resistance. It was invented in 1878 by the American astronomer Samuel Pierpont Langley.
Principle of operation
A bolometer ...
) power output is about 180 times that of the Sun. With a near-infrared J band magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
of −2.2, only Betelgeuse
Betelgeuse is a red supergiant of spectral type M1-2 and one of the largest stars visible to the naked eye. It is usually the tenth-brightest star in the night sky and, after Rigel, the second-brightest in the constellation of Orion ...
(−2.9) and R Doradus
R Doradus (HD 29712 or P Doradus) is a red giant variable star in the far-southern constellation Dorado. Its distance from Earth is . Having a uniform disk diameter of , it is thought to be the extrasolar star with the largest apparent ...
(−2.6) are brighter. The lower output in visible light is due to a lower efficacy
Efficacy is the ability to perform a task to a satisfactory or expected degree. The word comes from the same roots as ''effectiveness'', and it has often been used synonymously, although in pharmacology a pragmatic clinical trial#Efficacy versu ...
as the star has a lower surface temperature than the Sun.
As a single star, the mass of Arcturus cannot be measured directly, but models suggest it is slightly greater than that of the Sun. Evolutionary matching to the observed physical parameters gives a mass of ,[ while the oxygen isotope ratio for a first ]dredge-up A dredge-up is any one of several stages in the evolution of some stars. By definition, during a ''dredge-up'', a convection zone extends all the way from the star's surface down to the layers of material that have undergone fusion. Consequently, th ...
star gives a mass of .[ The star displays ]magnetic activity
A stellar magnetic field is a magnetic field generated by the motion of conductive plasma inside a star. This motion is created through convection, which is a form of energy transport involving the physical movement of material. A localized magn ...
that is heating the coronal structures, and it undergoes a solar-type magnetic cycle with a duration that is probably less than 14 years. A weak magnetic field has been detected in the photosphere
The photosphere is a star's outer shell from which light is radiated.
The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...
with a strength of around half a gauss
Johann Carl Friedrich Gauss (; german: Gauß ; la, Carolus Fridericus Gauss; 30 April 177723 February 1855) was a German mathematician and physicist who made significant contributions to many fields in mathematics and science. Sometimes refer ...
. The magnetic activity appears to lie along four latitudes and is rotationally modulated.[
Arcturus is estimated to be around 6 to 8.5 billion years old,][ but there is some uncertainty about its evolutionary status.][ Based upon the color characteristics of Arcturus, it is currently ascending the ]red-giant branch
The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass sta ...
and will continue to do so until it accumulates a large enough degenerate helium core
Core or cores may refer to:
Science and technology
* Core (anatomy), everything except the appendages
* Core (manufacturing), used in casting and molding
* Core (optical fiber), the signal-carrying portion of an optical fiber
* Core, the central ...
to ignite the helium flash
A helium flash is a very brief thermal runaway nuclear fusion of large quantities of helium into carbon through the triple-alpha process in the core of low mass stars (between 0.8 solar masses () and 2.0 ) during their red giant phase (the Sun is ...
.[ It has likely exhausted the ]hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, an ...
from its core and is now in its active hydrogen shell burning phase. However, Charbonnel et al. (1998) placed it slightly above the horizontal branch
The horizontal branch (HB) is a stage of stellar evolution that immediately follows the red-giant branch in stars whose masses are similar to the Sun's. Horizontal-branch stars are powered by helium fusion in the core (via the triple-alpha process) ...
, and suggested it has already completed the helium flash stage.[
]
Spectrum
Originally 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 VII ...
, Arcturus has evolved
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...
off the main sequence to the red giant branch
The red-giant branch (RGB), sometimes called the first giant branch, is the portion of the giant branch before helium ignition occurs in the course of stellar evolution. It is a stage that follows the main sequence for low- to intermediate-mass sta ...
, reaching an early K-type 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 grati ...
. It is frequently assigned the spectral type of K0III,[ but in 1989 was used as the spectral standard for type K1.5III Fe−0.5,][ with the suffix notation indicating a mild underabundance of iron compared to typical stars of its type. As the brightest K-type ]giant
In folklore, giants (from Ancient Greek: '' gigas'', cognate giga-) are beings of human-like appearance, but are at times prodigious in size and strength or bear an otherwise notable appearance. The word ''giant'' is first attested in 1297 fr ...
in the sky, it has been the subject of multiple atlases
An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth.
Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geographic ...
with coverage from the ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
to infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
.[
The spectrum shows a dramatic transition from ]emission line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...
s in the ultraviolet to atomic absorption line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ...
s in the visible range and molecular absorption lines in the infrared. This is due to the optical depth of the atmosphere varying with wavelength.[ The spectrum shows very strong absorption in some molecular lines that are not produced in the ]photosphere
The photosphere is a star's outer shell from which light is radiated.
The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it ...
but in a surrounding shell.[ Examination of ]carbon monoxide
Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...
lines show the molecular component of the atmosphere extending outward to 2–3 times the radius of the star, with the chromospheric wind steeply accelerating to 35–40 km/s in this region.[
Astronomers term "metals" those elements with higher ]atomic number
The atomic number or nuclear charge number (symbol ''Z'') of a chemical element is the charge number of an atomic nucleus. For ordinary nuclei, this is equal to the proton number (''n''p) or the number of protons found in the nucleus of every ...
s than helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...
. The atmosphere of Arcturus has an enrichment of alpha elements
Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first Letter (alphabet), letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician al ...
relative to iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in f ...
but only about a third of solar metallicity
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...
. Arcturus is possibly a Population II star
During 1944, Walter Baade categorized groups of stars within the Milky Way into stellar populations.
In the abstract of the article by Baade, he recognizes that Jan Oort originally conceived this type of classification in 1926:
Baade noticed th ...
.[
]
Oscillations
As one of the brightest stars in the sky, Arcturus has been the subject of a number of studies in the emerging field of asteroseismology
Asteroseismology or astroseismology is the study of oscillations in stars. Stars have many resonant modes and frequencies, and the path of sound waves passing through a star depends on the speed of sound, which in turn depends on local temperature ...
. Belmonte and colleagues carried out a radial velocity (Doppler shift of spectral lines) study of the star in April and May 1988, which showed variability with a frequency of the order of a few microhertz (μHz), the highest peak corresponding to 4.3 μHz (2.7 days) with an amplitude of 60 ms−1, with a frequency separation
Frequency separation within astrophysics, is a term used in both Helioseismology
Helioseismology, a term coined by Douglas Gough, is the study of the structure and dynamics of the Sun through its oscillations. These are principally caused by s ...
of c. 5 μHz. They suggested that the most plausible explanation for the variability of Arcturus is stellar oscillations.[
Asteroseismological measurements allow direct calculation of the mass and radius, giving values of and . This form of modelling is still relatively inaccurate, but a useful check on other models.][
]
Possible planetary system
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 ...
satellite astrometry
Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way.
His ...
suggested that Arcturus 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 wh ...
, with the companion about twenty times dimmer than the primary and orbiting close enough to be at the very limits of humans' current ability to make it out. Recent results remain inconclusive, but do support the marginal ''Hipparcos'' detection of a binary companion.[
In 1993, radial velocity measurements of Aldebaran, Arcturus and Pollux showed that Arcturus exhibited a long-period radial velocity oscillation, which could be interpreted as a ''substellar companion''. This ]substellar object
A substellar object, sometimes called a substar, is an astronomical object the mass of which is smaller than the smallest mass at which hydrogen fusion can be sustained (approximately 0.08 solar masses). This definition includes brown dwarfs and fo ...
would be nearly 12 times the mass of Jupiter
Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is b ...
and be located roughly at the same orbital distance from Arcturus as the Earth is from the Sun, at 1.1 astronomical unit
The astronomical unit (symbol: au, or or AU) is a unit of length, roughly the distance from Earth to the Sun and approximately equal to or 8.3 light-minutes. The actual distance from Earth to the Sun varies by about 3% as Earth orbits t ...
s. However, all three stars surveyed showed similar oscillations yielding similar companion masses, and the authors concluded that the variation was likely to be intrinsic to the star rather than due to the gravitational effect of a companion. So far no substellar companion has been confirmed.[
]
Mythology
One astronomical tradition associates Arcturus with the mythology around Arcas
In Greek mythology, Arcas (; Ancient Greek: Ἀρκάς) was a hunter who became king of Arcadia. He was remembered for having taught people the arts of weaving and baking bread and for spreading agriculture to Arcadia.
Family
Arcas was the so ...
, who was about to shoot and kill his own mother Callisto Callisto most commonly refers to:
*Callisto (mythology), a nymph
*Callisto (moon), a moon of Jupiter
Callisto may also refer to:
Art and entertainment
*''Callisto series'', a sequence of novels by Lin Carter
*''Callisto'', a novel by Torsten Kro ...
who had been transformed into a bear. Zeus averted their imminent tragic fate by transforming the boy into the constellation Boötes, called Arctophylax "bear guardian" by the Greeks, and his mother into Ursa Major (Greek: Arctos "the bear"). The account is given in Hyginus
Gaius Julius Hyginus (; 64 BC – AD 17) was a Latin author, a pupil of the scholar Alexander Polyhistor, and a freedman of Caesar Augustus. He was elected superintendent of the Palatine library by Augustus according to Suetonius' ''De Grammatic ...
's ''Astronomy
Astronomy () is a natural science that studies astronomical object, celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and chronology of the Universe, evolution. Objects of interest ...
''.[
]Aratus
Aratus (; grc-gre, Ἄρατος ὁ Σολεύς; c. 315 BC/310 BC240) was a Greek didactic poet. His major extant work is his hexameter poem ''Phenomena'' ( grc-gre, Φαινόμενα, ''Phainómena'', "Appearances"; la, Phaenomena), the fi ...
in his ''Phaenomena'' said that the star Arcturus lay below the belt of Arctophylax, and according to Ptolemy
Claudius Ptolemy (; grc-gre, Πτολεμαῖος, ; la, Claudius Ptolemaeus; AD) was a mathematician, astronomer, astrologer, geographer, and music theorist, who wrote about a dozen scientific treatises, three of which were of importanc ...
in the ''Almagest'' it lay between his thighs.[
An alternative lore associates the name with the legend around ]Icarius In Greek mythology, there were two people named Icarius (; grc, Ἰκάριος ''Ikários'').
*Icarius, a Spartan prince, son of Perieres.
*Icarius, an Athenian who received Dionysus.Apollodorus, 3.14.7
See also
*Icarus, whose wings failed in fli ...
, who gave the gift of wine to other men, but was murdered by them, because they had had no experience with intoxication and mistook the wine for poison. It is stated this Icarius, became Arcturus, while his dog, Maira, became Canicula (Procyon
Procyon () is the brightest star in the constellation of Canis Minor and usually the eighth-brightest star in the night sky, with an apparent visual magnitude of 0.34. It has the Bayer designation α Canis Minoris, which is Latinize ...
), although "Arcturus" here may be used in the sense of the constellation rather than the star.
Cultural significance
As one of the brightest stars in the sky, Arcturus has been significant to observers since antiquity.
In ancient Mesopotamia
Mesopotamia ''Mesopotamíā''; ar, بِلَاد ٱلرَّافِدَيْن or ; syc, ܐܪܡ ܢܗܪ̈ܝܢ, or , ) is a historical region of Western Asia situated within the Tigris–Euphrates river system, in the northern part of the F ...
, it was linked to the god Enlil
Enlil, , "Lord f theWind" later known as Elil, is an ancient Mesopotamian god associated with wind, air, earth, and storms. He is first attested as the chief deity of the Sumerian pantheon, but he was later worshipped by the Akkadians, Bab ...
, and also known as Shudun, "yoke",[ or SHU-PA of unknown derivation in the ''Three Stars Each'' ]Babylonian star catalogues
Babylonian astronomy collated earlier observations and divinations into sets of Babylonian star catalogues, during and after the Kassite rule over Babylonia. These star catalogues, written in cuneiform script, contained lists of constellations, i ...
and later MUL.APIN
MUL.APIN () is the conventional title given to a Babylonian compendium that deals with many diverse aspects of Babylonian astronomy and astrology.
It is in the tradition of earlier star catalogues, the so-called ''Three Stars Each'' lists, but ...
around 1100 BC.[
In ancient Greek the star is found in ancient astronomical literature, e.g. Hesiod's ''Work and Days'', circa 700 BC,][ as well as Hipparchus's and Ptolemy's star catalogs. The folk-etymology connecting the star name with the bears (Greek: ἄρκτος, arktos) was probably invented much later. It fell out of use in favour of Arabic names until it was revived in the ]Renaissance
The Renaissance ( , ) , from , with the same meanings. is a period in European history marking the transition from the Middle Ages to modernity and covering the 15th and 16th centuries, characterized by an effort to revive and surpass ideas ...
.[
]
In 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 ...
, Arcturus is one of two stars called ''al-simāk'' "the uplifted ones" (the other is Spica
Spica is the brightest object in the constellation of Virgo and one of the 20 brightest stars in the night sky. It has the Bayer designation α Virginis, which is Latinised to Alpha Virginis and abbreviated Alpha Vir or α Vir. Analys ...
). Arcturus is specified as السماك الرامح ''as-simāk ar-rāmiħ'' "the uplifted one of the lancer". The term ''Al Simak Al Ramih'' has appeared in Al Achsasi Al Mouakket catalogue (translated into Latin
Latin (, or , ) is a classical language belonging to the 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 the power of the ...
as ''Al Simak Lanceator'').[ This has been variously ]romanized
Romanization or romanisation, in linguistics, is the conversion of text from a different writing system to the Roman (Latin) script, or a system for doing so. Methods of romanization include transliteration, for representing written text, and ...
in the past, leading to obsolete variants such as ''Aramec'' and ''Azimech''. For example, the name ''Alramih'' is used in Geoffrey Chaucer
Geoffrey Chaucer (; – 25 October 1400) was an English poet, author, and civil servant best known for ''The Canterbury Tales''. He has been called the "father of English literature", or, alternatively, the "father of English poetry". He wa ...
's ''A Treatise on the Astrolabe
''A Treatise on the Astrolabe'' is a medieval instruction manual on the astrolabe by Geoffrey Chaucer. It describes both the form and the proper use of the instrument, and stands out as a prose technical work from a writer better known for poet ...
'' (1391). Another Arabic name is ''Haris-el-sema'', from ''حارس السماء'' ''ħāris al-samā’'' "the keeper of heaven".[ or ''حارس الشمال'' ''ħāris al-shamāl’'' "the keeper of north".][
In ]Indian astronomy
Astronomy has long history in Indian subcontinent stretching from pre-historic to modern times. Some of the earliest roots of Indian astronomy can be dated to the period of Indus Valley civilisation or earlier. Astronomy later developed as a dis ...
, Arcturus is called Swati or Svati
Svati ( sa, स्वाति, svāti, translit-std=IAST) is a feminine Hindu name that is a compound of + ('great goer', in reference to its remoteness) meaning 'very beneficent'. Probably referring to its brightness call "the real pearl" in ...
(Devanagari स्वाति, Transliteration IAST svāti, svātī́), possibly 'su' + 'ati' ("great goer", in reference to its remoteness) meaning very beneficent. It has been referred to as "the real pearl" in Bhartṛhari
Bhartṛhari (Devanagari: ; also romanised as Bhartrihari; fl. c. 5th century CE) was a Hindu linguistic philosopher to whom are normally ascribed two influential Sanskrit texts:
* the ''Vākyapadīya'', on Sanskrit grammar and linguistic philo ...
's kāvyas.
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 Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twe ...
, Arcturus is called ''Da Jiao'' (), because it is the brightest star in the Chinese constellation
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 Hellenistic t ...
called '' Jiao Xiu'' (). Later it became a part of another constellation '' Kang Xiu'' ().
The Wotjobaluk
The Wotjobaluk are an Aboriginal Australian people of the state of Victoria. They are closely related to the Wergaia people.
Language
R. H. Mathews supplied a brief analysis of the Wotjobaluk language (now known as Wergaia), describing what he ...
Koori
Koori (also spelt koorie, goori or goorie) is a demonym for Aboriginal Australians from a region that approximately corresponds to southern New South Wales and Victoria. The word derives from the Indigenous language Awabakal. For some people an ...
people of southeastern Australia knew Arcturus as ''Marpean-kurrk'', mother of ''Djuit'' (Antares
Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ S ...
) and another star in Boötes, ''Weet-kurrk''[ (Muphrid).][ Its appearance in the north signified the arrival of the larvae of the ]wood ant
The ''Formica rufa'' group is a subgeneric group within the genus ''Formica'', first proposed by William Morton Wheeler. This group contains the mound-building species of ''Formica'' commonly termed "wood ants" or "thatch-mound ants", which build ...
(a food item) in spring. The beginning of summer was marked by the star's setting with the Sun in the west and the disappearance of the larvae.[ The people of ]Milingimbi Island
Milingimbi Island, also Yurruwi, is the largest island of the Crocodile Islands group off the coast of Arnhem Land, Northern Territory, Australia.
Location
Milingimbi lies approximately east of Darwin, Northern Territory, Darwin and west of N ...
in Arnhem Land
Arnhem Land is a historical region of the Northern Territory of Australia, with the term still in use. It is located in the north-eastern corner of the territory and is around from the territory capital, Darwin. In 1623, Dutch East India Compan ...
saw Arcturus and Muphrid as man and woman, and took the appearance of Arcturus at sunrise as a sign to go and harvest ''rakia'' or spikerush
''Eleocharis'' is a virtually cosmopolitan genus of 250 or more species of flowering plants in the sedge family, Cyperaceae. The name is derived from the Greek words ἕλειος (''heleios''), meaning "marsh dweller," and χάρις (''charis' ...
.[ The ]Weilwan
The Weilwan (also known as Wayilwan, Wailwan, Ngiyampaa Wailwan and Ngemba Wailwan) are an Aboriginal Australian people of the state of New South Wales. They are a clan of the Ngiyampaa nation.
Name
The Weilwan ethnonym is derived from their wor ...
of northern New South Wales knew Arcturus as ''Guembila'' "red".
Prehistoric Polynesian navigators
Polynesian is the adjectival form of Polynesia. It may refer to:
* Polynesians, an ethnic group
* Polynesian culture, the culture of the indigenous peoples of Polynesia
* Polynesian mythology, the oral traditions of the people of Polynesia
* Poly ...
knew Arcturus as ''Hōkūleʻa'', the "Star of Joy". Arcturus is the zenith
The zenith (, ) is an imaginary point directly "above" a particular location, on the celestial sphere. "Above" means in the vertical direction (plumb line) opposite to the gravity direction at that location (nadir). The zenith is the "highest" ...
star of the Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kur ...
. Using Hōkūleʻa and other stars, the Polynesians launched their double-hulled canoes from Tahiti
Tahiti (; Tahitian ; ; previously also known as Otaheite) is the largest island of the Windward group of the Society Islands in French Polynesia. It is located in the central part of the Pacific Ocean and the nearest major landmass is Austr ...
and the Marquesas Islands
The Marquesas Islands (; french: Îles Marquises or ' or '; Marquesan: ' ( North Marquesan) and ' ( South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in th ...
. Traveling east and north they eventually crossed the equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can als ...
and reached the latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pol ...
at which Arcturus would appear directly overhead in the summer night sky. Knowing they had arrived at the exact latitude of the island chain, they sailed due west on the trade winds
The trade winds or easterlies are the permanent east-to-west prevailing winds that flow in the Earth's equatorial region. The trade winds blow mainly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisph ...
to landfall. If Hōkūleʻa could be kept directly overhead, they landed on the southeastern shores of the Big Island of Hawaii. For a return trip to Tahiti the navigators could use Sirius, the zenith star of that island. Since 1976, the Polynesian Voyaging Society
The Polynesian Voyaging Society (PVS) is a non-profit research and educational corporation based in Honolulu, Hawaii. PVS was established to research and perpetuate traditional Polynesian voyaging methods. Using replicas of traditional double-hul ...
's ''Hōkūleʻa
''Hōkūlea'' is a performance-accurate ''waa kaulua'', a Polynesian double-hulled voyaging canoe. Launched on 8 March 1975 by the Polynesian Voyaging Society, it is best known for its 1976 Hawaii to Tahiti voyage completed with exclusiv ...
'' has crossed the Pacific Ocean many times under navigators who have incorporated this wayfinding
Wayfinding (or way-finding) encompasses all of the ways in which people (and animals) orient themselves in physical space and navigate from place to place.
Wayfinding software is a self-service computer program that helps users to find a location, ...
technique in their non-instrument navigation.
Arcturus had several other names that described its significance to indigenous Polynesia
Polynesia () "many" and νῆσος () "island"), to, Polinisia; mi, Porinihia; haw, Polenekia; fj, Polinisia; sm, Polenisia; rar, Porinetia; ty, Pōrīnetia; tvl, Polenisia; tkl, Polenihia (, ) is a subregion of Oceania, made up of ...
ns. In the Society Islands
The Society Islands (french: Îles de la Société, officially ''Archipel de la Société;'' ty, Tōtaiete mā) are an archipelago located in the South Pacific Ocean. Politically, they are part of French Polynesia, an overseas country of the F ...
, Arcturus, called ''Ana-tahua-taata-metua-te-tupu-mavae'' ("a pillar to stand by"), was one of the ten "pillars of the sky", bright stars that represented the ten heavens of the Tahiti
Tahiti (; Tahitian ; ; previously also known as Otaheite) is the largest island of the Windward group of the Society Islands in French Polynesia. It is located in the central part of the Pacific Ocean and the nearest major landmass is Austr ...
an afterlife. In Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
, the pattern of Boötes was called ''Hoku-iwa'', meaning "stars of the frigatebird". This constellation marked the path for Hawaiʻiloa
Hawaiiloa (alt. Hawaii Loa or Ke Kowa i Hawaii) is a mythical Hawaiian fisherman and navigator who is said to have discovered the island of Hawaii.
Legend
Hawaiiloa was an expert fisherman and navigator who was famous for his lengthy fishing ex ...
on his return to Hawaii from the South Pacific Ocean. The Hawaiians called Arcturus ''Hoku-leʻa''. It was equated to the Tuamotuan constellation ''Te Kiva'', meaning "frigatebird
Frigatebirds are a family of seabirds called Fregatidae which are found across all tropical and subtropical oceans. The five extant species are classified in a single genus, ''Fregata''. All have predominantly black plumage, long, deeply forked ...
", which could either represent the figure of Boötes or just Arcturus. However, Arcturus may instead be the Tuamotuan star called ''Turu''. The Hawaiian name for Arcturus as a single star was likely ''Hoku-leʻa'', which means "star of gladness", or "clear star". In the Marquesas Islands
The Marquesas Islands (; french: Îles Marquises or ' or '; Marquesan: ' ( North Marquesan) and ' ( South Marquesan), both meaning "the land of men") are a group of volcanic islands in French Polynesia, an overseas collectivity of France in th ...
, Arcturus was probably called ''Tau-tou'' and was the star that ruled the month approximating January. The Māori
Māori or Maori can refer to:
Relating to the Māori people
* Māori people of New Zealand, or members of that group
* Māori language, the language of the Māori people of New Zealand
* Māori culture
* Cook Islanders, the Māori people of the C ...
and Moriori
The Moriori are the native Polynesian people of the Chatham Islands (''Rēkohu'' in Moriori; ' in Māori), New Zealand. Moriori originated from Māori settlers from the New Zealand mainland around 1500 CE. This was near the time of the ...
called it ''Tautoru'', a variant of the Marquesan name and a name shared with Orion's Belt
Orion's Belt or the Belt of Orion, also known as the Three Kings or Three Sisters, is an asterism in the constellation Orion. It consists of the three bright stars Alnitak
Alnitak is a triple star system in the constellation of ...
.
In Inuit astronomy, Arcturus is called the Old Man (''Uttuqalualuk'' in Inuit languages
The Inuit languages are a closely related group of indigenous American languages traditionally spoken across the North American Arctic and adjacent subarctic, reaching farthest south in Labrador. The related Yupik languages (spoken in western ...
) and The First Ones (''Sivulliik'' in Inuit languages).[
The ]Miꞌkmaq
The Mi'kmaq (also ''Mi'gmaq'', ''Lnu'', ''Miꞌkmaw'' or ''Miꞌgmaw''; ; ) are a First Nations people of the Northeastern Woodlands, indigenous to the areas of Canada's Atlantic Provinces and the Gaspé Peninsula of Quebec as well as the nort ...
of eastern Canada saw Arcturus as ''Kookoogwéss'', the owl.[
Early-20th-century Armenian scientist ]Nazaret Daghavarian
Nazaret Daghavarian ( hy, Նազարեթ Տաղավարյան, Western Armenian: Նազարէթ Տաղաւարեան, tr, Nazaret Dağavaryan; 1862 in Sebastia, Western Armenia, Ottoman Empire – 1915) was an Ottoman Armenian doctor, agrono ...
theorized that the star commonly referred to in Armenian folklore
The culture of Armenia encompasses many elements that are based on the geography, Armenian literature, literature, Armenian architecture, architecture, Armenian dance, dance, and Music of Armenia, music of the people.
Creative arts
Literatur ...
as ''Gutani astgh'' (Armenian
Armenian may refer to:
* Something of, from, or related to Armenia, a country in the South Caucasus region of Eurasia
* Armenians, the national people of Armenia, or people of Armenian descent
** Armenian Diaspora, Armenian communities across the ...
: Գութանի աստղ; lit. star of the plow) was in fact Arcturus, as 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 ...
of Boötes
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from la, Boōtēs, which comes from grc-gre, Βοώτης, Boṓtēs ...
was called "Ezogh" (Armenian
Armenian may refer to:
* Something of, from, or related to Armenia, a country in the South Caucasus region of Eurasia
* Armenians, the national people of Armenia, or people of Armenian descent
** Armenian Diaspora, Armenian communities across the ...
: Եզող; lit. the person who is plowing) by Armenians.[
]
In popular culture
In Ancient Rome
In modern historiography, ancient Rome refers to Roman civilisation from the founding of the city of Rome in the 8th century BC to the collapse of the Western Roman Empire in the 5th century AD. It encompasses the Roman Kingdom (753–509 B ...
, the star's celestial activity was supposed to portend tempestuous weather, and a personification of the star acts as narrator of the prologue to Plautus
Titus Maccius Plautus (; c. 254 – 184 BC), commonly known as Plautus, was a Roman playwright of the Old Latin period. His comedies are the earliest Latin literary works to have survived in their entirety. He wrote Palliata comoedia, the gen ...
' comedy ''Rudens
''Rudens'' is a play by Roman author Plautus. Its name translates from Latin as 'The Rope'. It is a comedy, which describes how a girl, Palaestra, stolen from her parents by pirates, is reunited with her father, Daemones, ironically, by means o ...
'' (circa 211 BC).[
The Karandavyuha sutra, compiled at the end of the 4th century or beginning of the 5th century, names one of ]Avalokiteśvara
In Buddhism, Avalokiteśvara (Sanskrit: अवलोकितेश्वर, IPA: ) is a bodhisattva who embodies the compassion of all Buddhas. He has 108 avatars, one notable avatar being Padmapāṇi (lotus bearer). He is variably depicted, ...
's meditative absorptions as "The face of Arcturus".[
One of the possible etymologies offered for the name "]Arthur
Arthur is a common male given name of Brittonic languages, Brythonic origin. Its popularity derives from it being the name of the legendary hero King Arthur. The etymology is disputed. It may derive from the Celtic ''Artos'' meaning “Bear”. An ...
" assumes that it is derived from "Arcturus" and that the late 5th to early 6th-century figure on whom the myth of King Arthur
King Arthur ( cy, Brenin Arthur, kw, Arthur Gernow, br, Roue Arzhur) is a legendary king of Britain, and a central figure in the medieval literary tradition known as the Matter of Britain.
In the earliest traditions, Arthur appears as a ...
is based was originally named for the star.[
In the ]Middle Ages
In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
, Arcturus was considered a Behenian fixed star
The Behenian fixed stars are a selection of fifteen stars considered especially useful for magical applications in the medieval astrology of Europe and the Arab world. Their name derives from Arabic ''bahman'', "root," as each was considered a s ...
and attributed to the stone Jasper
Jasper, an aggregate of microgranular quartz and/or cryptocrystalline chalcedony and other mineral phases,Kostov, R. I. 2010. Review on the mineralogical systematics of jasper and related rocks. – Archaeometry Workshop, 7, 3, 209-213PDF/ref> ...
and the plantain
Plantain may refer to:
Plants and fruits
* Cooking banana, banana cultivars in the genus ''Musa'' whose fruits are generally used in cooking
** True plantains, a group of cultivars of the genus ''Musa''
* ''Plantaginaceae'', a family of flowerin ...
herb. Cornelius Agrippa
Heinrich Cornelius Agrippa von Nettesheim (; ; 14 September 1486 – 18 February 1535) was a German polymath, physician, legal scholar, soldier, theologian, and occult writer. Agrippa's ''Three Books of Occult Philosophy'' published in 1533 drew ...
listed its kabbalistic
Kabbalah ( he, קַבָּלָה ''Qabbālā'', literally "reception, tradition") is an esoteric method, discipline and Jewish theology, school of thought in Jewish mysticism. A traditional Kabbalist is called a Mekubbal ( ''Məqūbbāl'' "rece ...
sign under the alternate name ''Alchameth''.[
Arcturus's light was employed in the mechanism used to open the 1933 Chicago World's Fair. The star was chosen as it was thought that light from Arcturus had started its journey at about the time of the previous Chicago World's Fair in 1893 (at 36.7 light-years away, the light actually started in 1896).][
At the height of the American Civil War, President Abraham Lincoln observed Arcturus through a 9.6-inch refractor telescope when he visited the Naval Observatory in Washington, DC, in August, 1863.]
References
Further reading
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External links
SolStation.com entry
{{DEFAULTSORT:Arcturus
K-type giants
Suspected variables
Hypothetical planetary systems
Arcturus moving group
Boötes
Bootis, Alpha
BD+19 2777
Bootis, 16
0541
124897
069673
5340
Stars named from the Ancient Greek language
TIC objects