Elderly Star（Canopus）, Bayer NoBottom seat α(Latinized asAlpha Carinae）, its apparent magnitude is -0.74, which is the southern constellationShip baseThe brightest star is also the second brightest star in the night sky, second only toSirius。It is about 310 light-years away from the Earth, with an absolute magnitude of - 5.71, and is one of the most luminous stars in hundreds of light-years around the sun.[15]
Old Man is one of the 58 navigation stars in the sky.Navigation stars are a series of the brightest and easiest to identify stars in the sky. They are extremely useful in the field of astronomical navigation.Old Man and the other two stars at the base of the ship（South Ship FiveandHaishi I）It forms the navigation star cluster at the southernmost end of the celestial sphere.At the same time, it is also the brightest star in the constellation Gondwanale, once namedSouth constellation α(Alpha Argus Navis, abbreviated asα Arg）, untilSouth seatIs split.[15]
The Old Man Star is located in the distant southern sky, at - 52 ° 41 ′ 44.38 "declination.This star is invisible to most northern observers because it cannot be seen north of latitude 37 ° 18 '.[15]
Chinese name
Elderly Star
Foreign name
Canopus
Alias
Alpha Carinae、HD 45348、HR 2326[15]
Classification
fixed star
Quality
8 M⊙（±0.3）
surface temperature
7400 K
Apparent magnitude
-0.72 etc
Absolute magnitude
-5.71 etc[5]
Rotation period
≥298 d
Right ascension
06:23:57.11s
Declination
-52°41′44.38″
Distance from ground
309.16 light years[32]
Spectrum type
A9 II
B-V color index
zero point one five
U-B color index
zero point one[6]
radial velocity
20.3±0.5 km/s
Self
Right ascension: 19.93 mas/yr;Declination: 23.24 mas/yr
Elderly Star[2]It's the southern constellationShip baseThe brightest A-type bright giant star in the middle is bluish white. It can be seen near the horizon in southern China.The luminosity isSolar luminosity10700 times the mass of the sun.The radius of the elder star is about 71 times that of the sun,Absolute magnitude-5.71, etc.[15]The star is difficult to observe and its luminosity is difficult to measure.In the 20th century, it was measured 196 light-years away from the earth.Its diameter is more than 70 times that of the sun, 310 light-years away.The old man star belongs to the ship base. Because its position is too far south, it cannot be observed in northern China. Only in the Yangtze River basin and places to the south can it be seen in the low sky in the southern sky for a short period of time. Therefore, people call it "the old man star in the South Pole" and "the immortal in the South Pole".[1]
Position of Canopus
The Elderly Star is bluish white, and its brightness is second only toSirius。You can see it near the south of ChinahorizonAppears at.The Elderly Star refers to the elderly in most cases.Contrary to Sirius' embarrassing situation, Old Man Star was always a lucky star in the eyes of ancient Chinese.[1]The Elderly Star (the first star in the Carina, the second star in the sky) is the brightest star in the Carina.It is believed that its English name (Canopus) derives from the captain of the expedition to Troy carrying Greek troops.staySpace agePreviously, it was difficult for humans to calculate the distance of the Elderly Star, so it was speculated that it was 1200 light-years away.
Elderly Star is the most powerful star within 700 light-years.
spectrum
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Before the 20th century, western scientists had little research on the Elderly Star.In 1897, it was endowed with F-type spectrum, which is the key toSageThe early extension of type I spectral classification is applicable to stars with relatively weak hydrogen lines and relatively strong calcium K lines.[16]It's inHenry Draper CatalogueThe standard star listed as F0 type spectrum in, the hydrogen line intensity of its spectrum type F0 is half of A0 type star, and the calcium K line intensity is three times of H δ.[17]American astronomer Jesse Greenstein usesMacDonald ObservatoryThe newly built Otto Struve telescope analyzed the spectrum of stars in detail.[18]In a paper in 1942, he pointed out that the spectrum of the old star was dominated by strong and wide hydrogen lines, as well as carbon, nitrogen, oxygen, sulfur, iron and many ionized metal absorption lines.[19]In 1966, the artificial satellite Gemini 11 studied it under ultraviolet light, and it was found that the surface temperature of the elderly star and the F0 supergiant was the same, about 6900 K.This is the data that Old Star was recognized at that time.[20]
New Zealand astronomers John Hernshaw and Krishna Desikachary studied spectra in more detail and published their results in 1982.[21-22]
When the luminosity level is classified according to the "Morgan Kener spectral classification method", the old star belongs to Iab type, indicating that it is of medium luminositySupergiant。This is based on the relative intensity of some spectral lines sensitive to the luminosity of stars.[23]And in the fifth editionBright star listIt is classified as F0II spectrum and belongs to the luminosity level of bright giant stars.[24]Balmer line[25](Balmer line) outline and oxygen line intensity indicate the size and luminosity of the old star.[26]
When considering the influence of the rotation speed of the star on the spectral lines, the Morgan Kener spectral type of the old star is adjusted to A9II.[27]Its spectrum is mainly composed ofAbsorption lineComposition, but some emission lines were also detected.For example, the calcium K line first observed in 1966 has weak launch wings on each side of the strong central absorption line.The emission line profile is usually related to the luminosity of stars described by the Wilson Bapp effect, but as far as old stars are concerned, their displayed luminosity is far lower than that calculated by other methods.[28]More detailed observations show that the emission line profile is variable, which may be related to the spectral area of the star surface.Emission lines can also be found in other spectral lines, such as H and K spectral lines of ionized magnesium.[29]
Physical characteristics
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The absorption line in the spectrum of the old man star will move slightly with a period of 6.9 days.This phenomenon was first detected in 1906Doppler effectThe change of is attributed to orbital motion.[39]At that time, the orbit was even calculated, but there was no such companion star in the old star, and the smallerradial velocity The changes are caused by the movement of the stellar atmosphere.The maximum radial velocity observed by it is only 0.7 to 1.6 km/s.The elder star also has a magnetic field that changes with the same period, which is through its spectral linesZeeman splittingDetected.[40]The old man is inmicrowaveIt is very bright at the wavelength ofradio wavesOne of the F-type stars detected.[41]Its rotation period is unclear, but it may exceed 300 days,[42]The measured approximate rotational speed is 9 km/s.[43]
In 1968, the old man starAngular diameterEarly stageInterferometryGivenEdge dimThe value is 6.86 mas, close to the recognized modern value[44]：Very long baseline radio interferometryLaw（VLBI）The measured angular diameter of Senecia is 6.9 mas.According to the calculation of the parallax of the Hipparcos satellite, the radius of the old planet is 71 times that of the sun.[7]If placed at the center of the solar system, it will engulf 90% of the region within the orbit of Mercury.[38]Its luminosity is 10700 times that of the sunHerotuIts position relative to the theoretical evolution trajectory in the solar system shows that its mass is 8.0 ± 0.3 times that of the sun.[7]
The old man star is aX-ray source, possibly by itsCoronaThe corona is heated to millions due to magnetic forceKelvin。Its temperature may be excited by the rapid rotation and the strong convection passing through the outer layer of the star.[45]Soft X-raySubcoronalX-raythanHard X-rayThe emission under the corona is much weaker.And in the constellation Perseus alpha（Tianchuan Three）OthersF-type supergiantThe same phenomenon was observed in.This phenomenon is considered to be a normal characteristic of such stars.[43]
distance
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stayIbaku satelliteBefore the launch, people's estimates of the distance of the old planet vary greatly, ranging from 96 light-years to 1200 light-years.The smaller value is obtained from parallax measurement (33 mas)[30]The larger value is derived from the assumption that the absolute magnitude of the elder star is very bright.[31]
Finally, the Ebagou satellite determined the distance between the old planet and the solar system as 309.16 light-years (94.79 seconds).This is based on the parallax measurement in 2007 (10.43 ± 0.53 mas).[32]At 95Second gapThe interstellar extinction degree of the old star is low, which is 0.26 magnitude.[33]The Old Man Star is too bright to be included inGaia satelliteAnd there is no Gaia parallax disclosed.[34]
At present, the elderly star isradial velocity Stay away from the sun.About 3.1 million years ago, it was the closest to the sun, about 172 light years (53Second gap）。Old Man orbits the Milky Way at a heliocentric speed of 24.5 km/s and a low eccentricity of 0.065.[3]
evolution
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The approximate position of the evolution of the old man star
The spectrum of Senecia shows that it has exhausted the hydrogen in its core and evolved far away from the main sequence band.In the main sequence belt, it spent about 30 million years as a blue white star with a mass about 10 times the mass of the sun.[15]The old man is inHerotuThe position in indicates that it is in the helium combustion phase.[7]It is a medium mass star, which left the branch of the red giant star before its core degenerated, and is now in theBlue rewind[35](Blue Loop) stage.[36]The stellar evolution model in the blue circle stage shows that the length of the blue circle is strongly affected by the internal rotation and mixing effects of stars.It is difficult to determine whether a star evolves to a higher temperature or returns to a lower temperature because the evolution tracks of stars with different masses overlap during the blue spiral.[5]
Senecia is located on the hotter side of the unstable zone, unlike those with similar luminosityCepheid variableIt pulsates like that.[37]However, its atmosphere does seem to be unstable, showing strong signs of convection.[5]
The mass of the old star may not be enough to fuse to iron and cause the core to collapse to formSupernova。On the contrary, it may eventually become a neon oxygen white dwarf star.[38]
cultural meaning
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Observation history
In IndiaVedic literature, Old Man Star and an ancient sageThrowing Mountain ImmortalOther sages are related to the Big Dipper.It is said that the star of Toushan Immortal is "the tranquilizer of water". Its rise andthe indian oceanThe calm of the sea coincides.It is believed to be the child of Prastiya, the son of Brahma.
stayancient GreekAnd the Roman mainland, but the Old Man StarAncient EgyptIt can be seen.Because it's below the horizon, soAlatosThe star was not recorded, butEratostheniandPtolemy The observation in Alexandria is called "Kan ō bos".[8]
Indian Navajo called it "Ma 'ii Biz' '.In SpainTenerifeThe myth of caring people, the Old Man Star is connected with the goddess Chasirahi.
Negev And SinaiBedouinAlso know this star, called Suhayl, and use it withPolaris is the main star for night navigationGuide star。Because it will disappear below the horizon, making it a factor that will change, instead of facing the 'unswerving' Polaris in the polar circle[9]。It also has an Arabic name: هيي (Suhayl, in Persian, Soheil), which was given by Muslim scientists in the 7th century.
In China, it is called Antarctic Elderly Star.Although in the capital of China in the Tang DynastyChang'anI can't see the old manDunhuang Star MapHas already appeared in.ChinaastronomerA row of stars drawn in 724 AD already have the old star and stars farther south[10]。however,The first record should beSima QianHe mentioned thatSiriusSimilar objects in the south[11]。In the traditional Chinese astronomical systemwell 's old manStar officialA star visible to the naked eye.
Yes, ancientPolynesiaPeople, inthe pacific oceanMany islands and atolls sail between bright stars that are important.When the horizon is low, these bright stars act as interstellar compasses to help sailors navigate to specific destinations.The elder star is the southern wing tip of the constellation called Manu, and Sirius is the body of this "great bird",Nanhe IIIIs the northern wing tip;Divide the night sky of the Polynesians into two hemispheres.Hawaiians call the Old Man Star Ke Alii-o-kona-i-ka-lewa, which means "the leader of the vast area in the south". This is where Hawaii and Ki goSouth Pacific One of the stars used when.
Maori people in New Zealand give the old star several different names.Ariki ("tall bear"), known as a lonely star, will make people cry and sing when it appears in the east;They also call it Atutahi, Aotahi or Atuatahi, "Stand Alone" (independent).Its loneliness shows that it is a forbidden star, and people who are "forbidden" are often lonely.Its appearance indicates the beginning of the "Maruaroa" season and predicts that winter is coming;The light towards the south predicts cold and wet winter, and towards the north predicts aWarm winter。Its appearance also foretells that food will be provided[12]。The name is also related to several myths.One story tells how Old Man Star was left outside the basket when the forest and the god of birds weaved the Milky Way.Another related myth said that Atutahi was Lance's first child. He refused to enter the Milky Way, so it was on the side of the Milky Way and rose earlier than the Milky Way.Other constellations and stars in Polynesia also use the same name.Kapae-poto、"Short horizon" refers to that he rarely rises and is seen in New Zealand;Kauanga ("Lonely One") is also the name of the Old Star, but only when it is the last one to be seen before sunriseStar timeThat's what I call it.
AfricabotswanaOfTswana calls the Old Man Star Naka.When it appears in the sky in the late winter, it indicates that more and more trees will lose their leaves and the wind will become stronger and stronger.The shepherd knows thatsheepandlivestockWhen they are raised in captivity[13]。South AfricaBo Zaman's Xam said that Old Man and Sirius aretermiteAnd the presence of flying ants.They also believe that bright stars have the ability to cause death and misfortune, and they will pray to Old Man and Sirius for good luck and skills.
stayBrazilMato GrossoThe Kalaparo people ofNanhe IIIIt's Kofongo "duck",Beihe IIAND ANDBeihe IIIRepresents its hand (wing).The appearance of this star cluster marks the coming of the rainy season and the staple food for entertaining guests on festivals,cassavaIncrease production.
The old man star symbolizes traditionSouth seatOfRudder[14]。In 1592, the British explorer Robert HughesTractatus de GlobisThe work ofObserverAttention to this starWater Commission IandAlpha All three areFirst-class star。He said: "This is something I have never seen in the UK. The brightest one is the rudder of the southern constellation of Cassiopeia, known as CanopusEridanaAt the end ofCentaurOn his right foot.
name
The English name of the Old Man Star Canopus means“SpartaThe navigator of King Menares' ship, named after the expedition carrying Greek troopsTroyThe captain of.The name "Canopus" includesTwo universalThe sources of are listed innaturalistRichard Hinckley Allen's Star Names: Their Lore and Meeting.One of them is derived fromTroy WarThe other is from EgyptCoptic"Kahi Nub" means the golden earth.Nearthe NileAt the mouth of the river, there is a ruined Egyptian port named after Canopus, which is located at the site of the Nile War.
stayArabicIn Chinese, the Old Man Star is called هيي.ancientPersiaThe astronomers and astrologers ofPersian literature Panchatantra, an animal fable written by the author, was later called The Lights of Canopus or Anvar-i-Suhaili.
The Elderly Star is the second brightest star in the sky, and is now calledShip baseAlpha stars.The ancients attached great importance to it. Unfortunately, it was too far south to be seen in the north of ChinaYangtze river basinAnd places to the south can see it in the low southern sky in a short period of time.Because of this, people also call it“antarcticOld Man Star "," Antarctic Fairy ", of course, it is far from the South Pole.Friends from the southFebruary in the lunar calendarIn the evening, find theSiriusThen, look downhorizonYou can find it at the top.Li BaiThere is a poem:“Hengshan MountainCangcang entersZimingLook down at the Old Man Star in AntarcticaNanyue Hengshan MountainYou can see the Old Man Star.Contrary to Sirius' embarrassing situation, Old Man Star was always a lucky star in the eyes of ancient Chinese.Astrologers believe that the appearance of the Old Man Star is a sign of peace in the world. Seeing this star will make the country prosperous and the people safe, so the poet has the sentence "Every healthy day in the sea, and the birthday star in the sky".Around 14000 AD, Old Man Star will becomeAntarctica。Longevity Star is the old man's star. It is also called Longevity Star because it focuses on longevity.
In Japan, the image of the Elderly Star "Shou Sen" is a symbol of good luckSeven Blessed Godsone of.
The sand hat follows the gull, and the boat is tied to this pavilion.The Jianghu is darker and whiter, and the pine and bamboo are far and slightly green.
One pillar should be near, and Gaotang should not pass again.Tonight, outside the South PoleElderly Star。
《True Spirit Karma Map》The "Antarctic Old Man Danling Shangzhen" is listed on the left side of Tai Chi.Later, in response to Chinese folk tradition, the two stars merged into one.The image of Shouxing is a white haired old man with white hair and childlike face. His face is kind. The crooked crutches he leans on must be high above his head.It is often used as a New Year picture pattern by Chinese people and is a symbol of good luck and longevity.
studies of the Book of ChangesIt is believed that the Old Star is a longevity star, a lucky star and a lucky star.Seeing it symbolizes that the world is at peace, the country is peaceful and the people are peaceful, good luck and full of hope for the future.
Taoism believes that the Antarctic fairy will bring good luck to all people in the way of coming down to earth at some time.
Observable time
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According to the news from Guangzhou on December 14 of China Broadcasting Network (reporter Zheng Shu, correspondent Li Jianji)Guangzhou Wuyang PlanetariumPreview: If the night sky is clear, you can watch the rare Old Man Star in Guangzhou in late December and even in southern China.Old man star is the second brightest star in the sky, its brightness is only second to Sirius.
In the evening of late December, there is no influence of moonlight, so it is very suitable to watch the Elderly Star in southern China.In Guangzhou, around 23:00, looking up at the night sky, you can see the brilliantOrionIn the southeast of Orion, Sirius, the brightest star in the sky, can be seen.In the south of Sirius, you can find a very bright star, which is the Old Man Star.Old Man is low in the south.In Guangzhou, the Elderly Star is the largestHorizon heightOnly 14 degrees.Therefore, to observe the Elderly Star, you should choose an environment with broad vision, dim lights and no obstructions in the south.
The old man is in the skyVisual position: Right ascension 6:24,Declination- 52 degrees and 42 minutes, over the southern hemisphere.TheoreticallyNorthern HemisphereThe old man star cannot be seen in the area north of 37 degrees north latitude.Due to atmospheric pressuredefinitionAnd lighting35 NIn the area south of DuDuhave a chance toSee it.
