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Alpha Centauri
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Alpha Centauri ABC is a multiple star
Location of Alpha Centauri History of Research Designations IRAS 14359-6037[1], SAO 252838[1], HD 128620J[1] and α Cen[1]
Observational data
(Epoch J2000. 0) Right ascension 14h 39m 36.5/35.1 s
Declination -60° 50 ' 02.3/13.8″
Distance 4.36 St. year
Apparent magnitude (V) -0,01/+1,34/+11,05
Constellation Centaurus
Astrometry Radial velocity (Rv) -21.6 km / s
Proper motion (μ) RA: -3678.19 mas per year
Dec: 481.84 mas per year
Parallax (π) 747.23±1.17 mas
Absolute magnitude (V) 4,38/5,71/15,49
Characteristics Spectral class G2V/K1V/M5, 5Ve
Color indicator (B − V) 0,65/0,85/1,97
Color indicator (U B) 0,24/0,64/1,54
Physical characteristics Weight 1,10/0,90/0,123[2] M☉
Radius 1,227/0,865/0,14 R☉
Age (6±1)* 109[3] years
Temperature 5,750/5,250[3]/2700 K
Luminosity 1,519/0,500/0,00006 L☉
Metallicity 130-230 %☉
Properties of gravity=4.30/4.37[4]
Elements of the orbit Period (P) 79.24 years
Semi major axis (a) 17.59"
The eccentricity (e) is 0.516
Inclination (i) 79.24°v
Node (Ω) 204.87°
Periastric epoch (T) 1955.56
[show]Other designations Rigil Kentaurus, Rigil Kent, Toliman, Bungula
CCDM J14396-6050, FK5 538, CPD −60°5483, GC 19728, α Cen A HD 128620, HIP 71683, HR 5459, LHS 50, SAO 252838, GCTP 3309.00, Gl 559 A,
α Cen B HD 128621, HIP 71681, HR 5460, LHS 51, Gl 559,
Proxima Cen
HIP 70890, LHS 49,
Information in SIMBAD databases data
ARICNS data
Sources: [5]
[information] in Wikidata
Coordinates: 14h 39m 36.5/35.1 s -60° 50 ' 02.3/13.8″
Alpha Centauri, α Centauri, α Centauri AB is a binary star in the constellation Centauri Both components, alpha Centauri A and alpha Centauri B, are visible to the naked eye as a single star -0.27 m, making alpha Centauri the third brightest star in the night sky.
Most likely, this system also includes the invisible to the naked eye red dwarf Proxima or alpha Centauri C, which is 2.2°away from the bright binary star.
All three are the closest stars to the Sun, and at the moment Proxima is somewhat closer to the others.
alpha Centauri has proper names: Rigel Centaurus (romanization of the Arab. [rill al qanatûr] — "Centaur's foot"), Bungula (possibly from the Latin ungula — "hoof") and Toliman (possibly from the Arabic. الللمان [al Zulman] "Ostriches")[7], but they are used quite rarely.
Designations in the main star catalogs: alpha Centauri A: HD 128620, HR 5459, CP 60°5483, GCTP 3309.00 A, LHS 50.
alpha Centauri B: HD 128621, HR 5460, GCTP 3309.00 B, LHS 51.
Content
[remove]
1 System characteristics 2 Observations 3 Planetary system 3.1 Alpha Centauri B b 3.2 Other possible planets
4 Interstellar flights 5 The closest environment of a star 6 Appearance in popular culture 7 See also 8 Notes 9 References
System characteristics[edit / edit wiki text]
Comparative dimensions of the components of the alpha Centauri system and the Sun
D the two main stars α Centauri A and α Centauri B belong to the main sequence and are close in characteristics to the Sun. alpha Centauri A turned out to be the first star for which it was possible to conduct a direct observation of the atmosphere, which showed its similarity to the luminary of our system (a thin cold layer was found in the atmosphere).
The age of the system is estimated at 6 billion years, which is more than the age of the Sun, which is 4.5 billion years.
Both stars rotate around a common center of mass in an elliptical orbit with an eccentricity of 0.52 and a large semi axis of 23.4 au.
The orbital period is 79.91 years.
Their trigonometric parallax is equal to 742.1 ± 1.4 angular milliseconds.
The proper motion of stars A and B is equal to -3.643 ± 0.012 arcseconds per year in direct ascension and +0.697 ± 0.009 arcseconds per year in declination, the radial velocity is -22.445 ± 0.0024 km / s.
The maximum angular distance on the celestial sphere between them is approximately 22".
The inclination of the orbit of the star pair alpha Centauri A and B to the picture plane of the observer from Earth is 79.205 ± 0.041 degrees, that is, the orbit of the system is observed almost from the edge, which increases the probability of detecting planets in the system by the transit method.
The kinematic characteristics of Proxima Centauri differ from those of the main stars of the system.
Proxima is separated from alpha Centauri AB on the celestial sphere by an angular distance of about 2°, which is 4 times the angular diameter of the Moon.
Proxima Centauri (Latin proxima — "nearest") is located approximately 15,000 ± 700 AU (about 0.21 sv. year) from the two central luminaries of the system.
The period of Proxima's rotation around alpha Centauri AB is about 500 thousand years.
The coordinates of α Centauri A:
Right ascension α2000 = 14h39m36c, 5 Declination δ2000 = -60°50 ' 02"
Coordinates of α Centauri B:
Right ascension α2000 = 14h39m35c, 1 Declination δ2000 = -60°50 ' 13"
Characteristics of the components of the system α Centauri α Centauri A α Centauri B Proxima Centauri Absolute magnitude 4.38 5.71 15.53 Spectral class G2V K1V M5, 5Ve Luminosity (in solar) 1,519 0,5 6·10-5 Diameter (in solar) 1.227 0.865 0.14 Distance to the Sun, sv.
years 4.36 4.22
Observations[edit / edit wiki text]
The closest environment of the Sun.
The main stars of the A and B system are too close to each other to be distinguished with the naked eye, since the angular distance between them varies between 1.7 and 22 angular seconds[10] but, thanks to their orbits, both stars are easily distinguishable using binoculars or small (about 5 cm in diameter) telescopes.
In 2010, the angular distance between the components was 6.74 arcseconds, in 2011-6.04 arcseconds.
The angular distance between the components is decreasing and will become minimal (4 arc seconds) in February 2016.
The greatest angular distance between the components of the system was last observed in February 1976, the next one will occur in January 2056.
In the southern hemisphere, Alpha Centauri forms the outer star of Pointers or Southern Pointers (navigational asterism)[11], so named because the line through Beta Centauri (Hadar, Agena)[12], 4.5° to the west[11], points directly to the constellation of the Southern Cross[11].
"Pointers" easily distinguish a real Southern Cross from a False Cross[13].
South of 29° south latitude, Alpha Centauri is a non descending star and never sets below the horizon[14].
Just like the Southern Cross, this system is too far to the south to be visible to an observer from the middle northern latitudes.
South of approximately +29° north latitude (i.e. south of Delhi, Kuwait and Houston) and to the equator during the northern summer, Alpha Centauri is visible close to the horizon in the south[12].
The culmination of the star occurs annually at midnight on April 24 or at 21: 00 on June 8[12][15].
Planetary system[edit / edit wiki text]
Alpha Centauri B b[edit / edit wiki text]
The observations carried out for a long time could not detect planets in the Alpha Centauri system[16][17].
Only on October 16, 2012, astronomers of the European Southern Observatory announced the discovery of the planet Alpha Centauri B b with a mass close to Earth's, in orbit around alpha Centauri B[18][19].
The planet was discovered by measuring the fluctuations of radial velocities using the HARPS spectrograph.
For this, astronomers needed more than four years of observations[20].
The Geneva group observed the spectrum of the star Alpha Centauri B from February 2008 to July 2011.
A total of 459 measurements of the radial velocity were made, the accuracy of a single measurement was 0.8 m / sec.
Such a large amount of accumulated data allowed us to identify and take into account various sources of noise: stellar fluctuations (the surface of the star Alpha Centauri B fluctuates slightly with periods of less than 5 minutes), surface granulation, the influence of spots on the average radial velocity of the star, long term activity associated with the magnetic field, etc.
The matter was partly facilitated by the fact that the brightness of Alpha Centauri B, like many other orange dwarfs of the spectral classes K0 V and K1 V, is exceptionally stable.
It was believed that planet b is very close to the sun, at 0.04 AU (6 million km), without falling into the habitable zone.
The period of rotation around the star is estimated at 3,236 days, and the minimum mass of the planet is about 1.13 Earth.
In October 2015, the planet was "closed", as it was proved that the 3.26 day RV signal in the measurements of the Geneva group appeared due to the peculiarities of mathematical data processing[21][22].
Other possible planets[edit / edit wiki text]
A view from a hypothetical planet orbiting Alpha Centauri A, in the artist's view.
Alpha Centauri B is the bright star on the left
The proposed planets may orbit separately around alpha Centauri A or alpha Centauri B, or may have large orbits around the alpha Centauri AB binary system.
Since both stars are approximately similar to the Sun (for example, in age and metallicity), astronomers are particularly interested in finding planets in this system.
Several teams that have announced their research in this direction use various methods of radial velocity or star passage to study this system.
Computer simulations have shown the possibility of forming a planet within 1.1 AU (160 million km) from alpha Centauri B, and that the orbit of this planet can remain stable for at least 250 million years.
Bodies around A can orbit at slightly larger distances, due to the stronger gravity of A. In addition, the absence of brown dwarfs and gas giants around A and B, on the contrary, increases the chances of detecting Earth type planets.
As of 2002, the technology did not allow us to detect the planets of the Earth group around Alpha Centauri.
But theoretical calculations of the detection capabilities by the radial velocity method have shown that targeted and regular studies with a class 1m telescope can with a high probability detect a hypothetical planet with a mass of 1.8 Earth masses in the habitable zone of alpha Centauri B within three years.
According to observations of the Hubble Space Telescope in 2013 and 2014 for the star Alpha Centauri B, scientists have suggested the possibility of the existence of a planet about the size of Earth orbiting Alpha Centauri B in less than 20.4 days One of the 2012 studies conducted by astronomers from the University of Edinburgh shows that the star alpha Centauri B has a habitable zone at a distance of at least 0.5 and not more than 0.9 AU from the star.
At the same time, the average surface temperature of a hypothetical planet within this zone will differ by only 4-5 kelvins, depending on the distance to the second star alpha Centauri A.
The simulation shows that a planet orbiting alpha Centauri B will only approach the star alpha Centauri A once every 70 years at a distance at which this star will affect the planet's climate.
The rest of the time, it will not affect the climate of the planet.
The researchers also note that such scenarios are possible only if there are oceans on the planet similar to those on Earth If the planet is a dry desert, like Mars, then the temperature fluctuations will be much stronger.
31].
Interstellar flights[edit / edit wiki text]
It is assumed that Alpha Centauri will be the first target of interstellar flights.
It is assumed that Alpha Centauri will be the first target of interstellar flights.
It is impossible to overcome the distance between the Sun and Alpha Centauri using modern technologies in a reasonable time.
It is impossible to overcome the distance between the Sun and Alpha Centauri using modern technologies in a reasonable time.
However, the capabilities of solar sail technologies or a nuclear rocket engine can allow such a flight to be made in several decades.
32].
The closest environment of the star[edit / edit wiki text]
The following star systems are located within 10 light years from the Alpha Centauri system:
Star Spectral class Distance, St. Luman 16 AB L7.
5 / T0.
5 3.68 Sun G2 V 4.4 Barnard's Star M4.
0 V 6.5 Ross 154 M3.
5 Ve 8.1 Wolf 359 M5.
8 Ve 8.3 Sirius AB A1 V / DA2 VII 9.5 Epsilon Eridani K2 Ve 9.7
Appearance in popular culture[edit / edit wiki text]
Since this star system is the closest to us, science fiction writers have long associated with it the beginning of the era of interstellar flights.
In Stanislav Lem's novel "The Magellanic Cloud", the first spaceship of earthlings "Gaia"is sent to Alpha Centauri.
The writer dated this flight to 3114.
In the computer game Sid Meier's Civilization, one of the possible ways to win is to build and successfully deliver a starship with colonists to Alpha.
The action of Sid Meier's Alpha Centauri — one of the sequels of Civilization takes place on the fictional planet Chiron, orbiting around the specified star, in the sequel of the game, presumably the same thing happens as Alpha Centauri In the Alpha Centauri system, director James Cameron placed the planet Pandora, where the action of the science fiction film "Avatar"takes place.
According to the film, Pandora is the largest satellite of the gas giant Polyphemus, which in turn is the planet of the star Alpha Centauri[33].
In Isaac Asimov's book "The Academy and the Earth", the nearest inhabited planet belongs to this star system.
A starship in Robert Heinlein's novel "Stepsons of the Universe"is heading for Proxima Centauri in 2119.
In the computer game "Alien Legacy" it is mentioned that hostile intelligent beings live in the Alpha Centauri system, who have unleashed and are winning a war with Earth.
This is why the colony ship (which is the original base in the game) was sent to the remote Beta Cutter system.
In the computer game "StarCraft", human colonies are founded in the Alpha, Beta and Proxima Centauri star systems under the control of the United Earth Directorate (UCD).
The action of the computer games "Killzone 2" and "Killzone 3" takes place on the hostile planet Helgan, which, in turn, is located in the Alpha Centauri system.
In Transformers, the planet Cybertron was located in the Alpha Centauri system.
In the film "Guest from the future" Kolya Gerasimov meets with aliens from Alpha Centauri.
In the film "This funny planet", the heroes of L. Kuravlev, V. Sergachev and E. Vasilyeva are aliens from Alpha Centauri In the film "Amazing Berendeev", the main character designs a transmitter to send a signal to his brothers in mind in the Alpha Centauri system.
In William Gibson's novels "Neuromancer","Winter Silence"/"Neuromancer" and "Mona Lisa Overdrive", the Collin construct is mentioned as a system in which an extraterrestrial civilization was discovered by listening to radio radiation.
In the film "The Distant Blue Sky", using the example of Alpha Centauri, the main character tells about the huge distances in space.
In the movie" Alien", Earth is at war with the attacking forces from Alpha Centauri.
(See also en: Alpha Centauri in fiction)
See also[edit / edit wiki text]
Alpha Centauri in Wikicitatnik?
Alpha Centauri on Wikimedia Commons?
Alpha Centauri in Wikinews?
Alpha Centauri B b List of nearest stars List of brightest stars
Notes[edit / edit wiki text]
↑ Show compactly
↑ Go to: 1 2 3 4 SIMBAD Astronomical Database ↑ Anosova, J.; Orlov, V. V.; Pavlova, N. A. (1994). "
Dynamics of nearby multiple stars.
The alpha Centauri system».
Astronomy and Astrophysics 292 (1): 115-118.
Verified on May 16, 2008.
Перейти Go to: 1 2 England, M. N. (1980).
"A spectroscopic analysis of the Alpha Centauri system".
Monthly Notices of the Royal Astronomical Society 191: 23–35.
Verified on May 16, 2008.
↑ Gilli, G.; Israelian, G.; Ecuvillon, A.; Santos, N. C.; Mayor, M. (2006).
«Abundances of Refractory Elements in the Atmospheres of Stars with Extrasolar Planets».
Astronomy and Astrophysics 449 (2): 723-736.
DOI:10.1051/0004-6361:20053850.
Checked on 2007-06-01.
↑ [1] (unavailable link) ↑ Surdin V. G. Stars.
- Moscow: Fizmatlit, 2009.
- pp.
95-99.
↑ Kunitzsch P., & Smart, T., A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations, Cambridge, Sky Pub.
Corp., 2006, p.
27. Космос Cosmos magazine: The Atmosphere of the nearest star ↑ Hartkopf, W., Mason, D. M..
Sixth Catalog of Orbits of Visual Binaries, U.S. Naval Observatory.
↑ Van Zyl Johannes Ebenhaezer.
Unveiling the Universe: An Introduction to Astronomy.
— Springer, 1996.
— ISBN 3540760237.
↑ Go to: 1 2 3 4 Hartung, E. J., Frew, David Malin, David.
Astronomical Objects for Southern Telescopes, Cambridge University Press.
Перейти Go to: 1 2 3 Norton, A. P., Ed. I. Ridpath.
Norton's 2000.0 :Star Atlas and Reference Handbook.
— Longman Scientific and Technical, 1986.
— P. 39–40.
↑ Mitton Jacquelin.
The Penguin Dictionary of Astronomy.
— Penguin Books, 1993.
— P. 148.
↑ This is calculated for a fixed latitude by knowing the star’s declination (δ) using the formulae (90°+ δ).
Alpha Centauri’s declination is −60° 50′, so the latitude where the star is circumpolar will be south of −29° 10′S or 29°.
Similarly, the place where Alpha Centauri never rises for northern observers is north of the latitude (90°+ δ) N or +29°N. ↑ 'The '"Constellations : Part 2 Culmination Times"'.
Southern Astronomical Delights.
Checked on August 6, 2008.
Archived from the original source on February 4, 2012.
↑ Go to: 1 2 Why Havenot Planets Been Detected around Alpha Centauri.
Universe Today.
Verified on April 19, 2008.
Archived from the original source on February 4, 2012.
↑ Tim Stephens.
Nearby star should harbor detectable, Earth like planets.
News & Events.
UC Santa Cruz (March 7, 2008).
Verified on April 19, 2008.
Archived from the original source on February 4, 2012.
↑ SETH BORENSTEIN.
Earth Sized Planet Found Just Outside Solar System (English).
abc News (17.10.2012).
Verified on October 17, 2012.
Archived from the original source on October 20, 2012.
НИКОЛАЙ NIKOLAY PODORVANYUK, ANNA SABUROVA.
Earth is in Alpha Centauri.
Gazeta.ru (17.10.2012).
Verified on October 17, 2012.
Archived from the original source on October 20, 2012.
↑ Mike Wall.
Discovery!
Earth Size Alien Planet at Alpha Centauri Is The Closest Ever Seen.
space.com (16.10.2012).
Verified on October 17, 2012.
Archived from the original source on October 20, 2012.
Gh Ghost in the time series: no planet for Alpha Cen B ↑ Planetary scientists have denied the discovery of a planet near Alpha Centauri ↑ Scientific world news: there may be terrestrial planets in Alpha Centauri ↑ Exoluna in the habitable zone ↑ Theorists "found" stone planets near Alpha Centauri ↑ Thebault, P., Marzazi, F., Scholl, H. (2009).
"Planet formation in the habitable zone of alpha centauri B".
Monthly Notices of the Royal Astronomical Society 393: L21–L25.
DOI:10.1111/j.1745-3933.2008.00590.x. Bibcode: 2009MNRAS.393L..21T.
Перейти Go to: 1 2 Quintana, E. V.; Lissauer, J. J.; Chambers, J. E.; Duncan, M. J.; (2002).
"Terrestrial Planet Formation in the Alpha Centauri System".
Astrophysical Journal 2 (2).
DOI:10.1086/341808.
Bibcode: 2002ApJ...576..982Q.
↑ Javiera M. Guedes, Eugenio J. Rivera, Erica Davis, Gregory Laughlin, Elisa V. Quintana, Debra A. Fischer (2008).
«Formation and Detectability of Terrestrial Planets Around Alpha Centauri B».
Astrophysical Journal 679 (2): 1582–1587.
DOI:10.1086/587799.
Bibcode: 2008ApJ...679.1582G.
↑ [1503.07528] Hubble Space Telescope search for the transit of the Earth mass exoplanet Alpha Centauri Bb ↑ Astronomers suspected the presence of another super earth in Alpha Centauri ↑ A planet in the habitable zone around alpha Centauri B is modeled.
compulenta.ru (March 26, 2012).
↑ Ian O'Neill, Ian.
How Long Would it Take to Travel to the Nearest Star?.
Universe Today (July 8, 2008).
Archived from the original source on February 4, 2012.
Астро Astronomers have found the birthplace of "Avatar" - PHOTO.
Day.
Az (December 31, 2013).
Checked on January 3, 2014.
Archived from the original source on January 3, 2014.
Links[edit / edit wiki text]
Alpha Centauri Alpha Centauri 3 (Solstation) data from the SIMBAD observatory Alpha Centauri Planetary System on the "Planetary Systems" website http://allplanets.ru/star.php?star=HD%20128621
[hide] Stars of the constellation Centauri Bayer α (Rigel Ketaurus/Toliman) * β (Hadar/Agena) • γ • δ • ε • ζ • n * θ (Menkent) • i • κ • λ • μ • v • ξ1 • ξ2 • o1 • o2 • π • p • σ • τ • u1 • u2 • φ • χ • ψ • a • b • c1 • c2 • d • e • f • g • h • i • j • k • l • m • n • p • r • u • v • w • x1 • x2 • y • z • A • B • C1 • C2 • C3 • D • E • F • G • H • J • K • M • N • Q Flamsteed 1 (i) • 2 (g) • 3 (k) • 4 (h) • 5 (θ, Menkent) Other V766 Centauri List
<img src="//ru.wikipedia.org/wiki/Special:CentralAutoLogin/start?type=1x1" alt="" title="" width="1" height="1" style="border: none; position: absolute;" />
Source — "https://ru.wikipedia.org/w/index.php?title=Alpha Centauri&oldid=75110613"
Categories: Triple stars Yellow dwarfs Orange dwarfs Red dwarfs Stars alphabetically Stars of the constellation Centauri Centauri (constellation) Nearest to the Sun Stars Planetary systems Bayer objects
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