FACTOID # 16: In the 2000 Presidential Election, Texas gave Ralph Nader the 3rd highest popular vote count of any US state.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Alpha centauri
Alpha Centauri A[1]/B[2]

The position of Alpha Centauri.
Observation data
Epoch J2000
Constellation
(pronunciation)
Centaurus
Right ascension 14h 39m 36.4951/35.0803s
Declination -60° 50′ 02.308/13.761″
Apparent magnitude (V) -0.01/+1.33
Characteristics
Spectral type G2V/K2IV
U-B color index +0.23/+0.63
B-V color index +0.69/+0.90
Variable type None
Astrometry
Radial velocity (Rv) -21.6 km/s
Proper motion (μ) RA: -3678.19 mas/yr
Dec.: 481.84 mas/yr
Parallax (π) 747.23 ± 1.17 mas
Distance 4.365 ± 0.007 ly
(1.338 ± 0.002 pc)
Absolute magnitude (MV) 4.38/5.71
Details
Mass 1.100/0.907[3] M
Radius 1.227/0.865[3] R
Surface gravity (log g) 4.30/4.37[4]
Luminosity 1.519/0.500[3] L
Temperature 5,790/5,260[3] K
Metallicity 151/160%[3] Sun
Age 4.85×109[3] years
Visual binary orbit[5]
Companion Alpha Centauri AB
Period (P) 79.9 yr
Semimajor axis (a) 17.59"
Eccentricity (e) 0.519
Inclination (i) 79.23°
Longitude of the node (Ω) 204.82°
Periastron epoch (T) 1955.59
Argument of periastron (ω) 231.80°
Visual binary orbit[6]
Companion Alpha Centauri AB
Period (P) 79.91 yr
Semimajor axis (a) 17.57"
Eccentricity (e) 0.5179
Inclination (i) 79.205°
Longitude of the node (Ω) 204.85°
Periastron epoch (T) 1875.66
Argument of periastron (ω) 231.65°
Database references
SIMBAD data
ARICNS data
Other designations
Rigil Kentaurus, Rigil Kent, Toliman, Bungula, FK5 538, CP(D)−60°5483, GC 19728, CCDM J14396-6050

α Cen A Wikipedia does not have an article with this exact name. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... This article is about the star grouping. ... From the dawn of time, poop observed the sky and grouped stars into patterns or constellations. ... Centaurus (Latin for centaur) was one of the 48 constellations listed by Ptolemy, and counts also among the 88 modern constellations. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... This article or section contains a plot summary that is overly long or excessively detailed. ... Illustration of the use of optical wavelength interferometry to determine precise positions of stars. ... Radial velocity is the velocity of an object in the direction of the line of sight. ... kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s-1. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... For other uses, see Parallax (disambiguation). ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... Distance is a numerical description of how far apart objects are at any given moment in time. ... A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one year. ... A parsec is the distance from the Earth to an astronomical object which has a parallax angle of one arcsecond. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standard luminosity distance away from us, in the absence of interstellar extinction. ... For other uses, see Mass (disambiguation). ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... This article is about an authentication, authorization, and accounting protocol. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... The surface gravity of a Killing horizon is the acceleration, as exerted at infinity, needed to keep an object at the horizon. ... This article does not cite any references or sources. ... The solar luminosity, , is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... For other uses, see Temperature (disambiguation). ... For other uses, see Kelvin (disambiguation). ... The globular cluster M80. ... This article is about the astronomical object. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... For the band, see Binary Star (band). ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... For the science fiction novella by William Shunn, see Inclination (novella). ... It has been suggested that this article or section be merged into Orbital node. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... The argument of periapsis (ω) is the orbital element describing the angle of an orbiting bodys periapsis (the point of closest approach to the central body), relative to its ascending node (the point where the body crosses the plane of reference from South to North). ... For the band, see Binary Star (band). ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... In geometry, the semi-major axis (also semimajor axis) a applies to ellipses and hyperbolas. ... In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... For the science fiction novella by William Shunn, see Inclination (novella). ... It has been suggested that this article or section be merged into Orbital node. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... The argument of periapsis (ω) is the orbital element describing the angle of an orbiting bodys periapsis (the point of closest approach to the central body), relative to its ascending node (the point where the body crosses the plane of reference from South to North). ... SIMBAD (the Set of Identifications, Measurements, and Bibliography for Astronomical Data) is a database of astronomical information about objects within the Milky Way. ... A star catalogue, or star catalog, is an astronomical catalog that lists stars. ... Fifth Fundamental Catalogue is a glossary of positions of stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ...


Gl 559 A, HR 5459, HD 128620, GCTP 3309.00, LHS 50, SAO 252838, HIP 71683 In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... Smithsonian Astrophysical Observatory Star Catalog contain the 258,996 stars. ... The Hipparcos and Tycho Catalogues (Tycho-1) are the primary products of the European Space Agencys astrometric mission, Hipparcos. ...


α Cen B


Gl 559 B, HR 5460, HD 128621, LHS 51, HIP 71681 In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Hipparcos and Tycho Catalogues (Tycho-1) are the primary products of the European Space Agencys astrometric mission, Hipparcos. ...


α Cen C (= Proxima Cen)

LHS 49, HIP 70890

Alpha Centauri / α Centauri / α Cen, also known as Rigil Kentaurus, Rigel Kent, or Toliman, is the brightest star in the southern constellation of Centaurus and an established binary star system, Alpha Centauri AB (α Cen AB). It appears to the naked-eye as the third brightest star in the entire night sky, being only outshone by Sirius and Canopus. By total visual magnitude Alpha Centauri AB is −0.27, which is just fractionally brighter than the fourth brightest individual star in the night sky, Arcturus. In astronomy, many stars are referred to simply by catalogue numbers. ... The Hipparcos and Tycho Catalogues (Tycho-1) are the primary products of the European Space Agencys astrometric mission, Hipparcos. ... This article is about the astronomical object. ... This article is about the star grouping. ... Centaurus (Latin for centaur) was one of the 48 constellations listed by Ptolemy, and counts also among the 88 modern constellations. ... For the band, see Binary Star (band). ... This article is about the brightest star in the night sky of Earth. ... This article does not cite any references or sources. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... For other uses, see Arcturus (disambiguation). ...


In the southern hemisphere Rigel Kent is known as one of The Pointers, along with Beta Centauri or Agena / Hadar, as both stars directly point towards the constellation Crux - the Southern Cross. The Pointers were so named because they easily distinguish the true Southern Cross from the asterism known as the False Cross. The star Beta Centauri lies some 4.4 degrees further west from Alpha Centauri, mid-way between the Southern Cross and α Centauri. Both stars are too far south to be visible for most northern hemisphere observers. Beta Centauri (β Cen / β Centauri), also known as Hadar or Agena, is the second brightest star in the constellation Centaurus and the eleventh brightest star in the nighttime sky. ... This article is about the star grouping. ... CRUX is a lightweight, i686-optimized Linux distribution targeted at experienced Linux users. ... Southern Cross is the English name of Crux Australis, a constellation visible in the Southern Hemisphere. ... In astronomy, an asterism is a pattern of stars seen in Earths sky which is not an official constellation. ... Vela (pronounced , Latin: ) is a southern constellation, one of the four parts into which Argo Navis was split (the others being Carina, Puppis and Pyxis). ... Beta Centauri (β Cen / β Centauri), also known as Hadar or Agena, is the second brightest star in the constellation Centaurus and the eleventh brightest star in the nighttime sky. ... This article describes the unit of angle. ...


Those that can see α Centauri will find it lying close to the southern horizon during their northern summer. From south of about -33 degrees latitude, α Centauri is circumpolar and never sets below the horizon. Circumpolar stars are those stars which are located near the celestial poles of the celestial sphere, i. ...


Alpha Centauri has the primary distinction of being the closest of all the stars visible to the naked eye in the night sky. Its distance is about 1.3 parsecs, or 4.37 light years. A parsec is the distance from the Earth to an astronomical object which has a parallax angle of one arcsecond. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ...

Contents

Nature of Alpha Centauri

Alpha Centauri is a triple star system. The brightest two stars make a close orbiting binary; an additional much more distant and fainter companion is called Proxima Centauri, Proxima or α Cen C. Individually, the two bright stars rate, respectively, as the fourth and twenty-first brightest stars in the sky (excluding the Sun). A star system or stellar system is a small number of stars that orbit each other,[1] bound by gravitational attraction. ... For the band, see Binary Star (band). ... Proxima Centauri (Latin proximus, -a, -um: meaning next to or nearest to)[4] is a red dwarf star that is likely a part of the Alpha Centauri star system and is the nearest star to the Sun at a distance of 4. ... Bright stars can be bright because they produce more light, because they are closer to us, or both. ...


Observationally, α Centauri AB is too close to be resolved by the naked eye. However, for more than two centuries it has been very well observed and measured by telescopes as small as 5 cm in aperture.


Observational History of Alpha Centauri

Its duplicity, according to the renowned double star observer Robert Aitken (1961), and as now stated in the 6th Catalog of Binary Stars (2008), was originally discovered in December 1689 by Father Richaud from the city of Pondicherry in India while he was observing a comet. Sir John Herschel in 1834 was then the first to make micrometrical observations, though astrometric positions were made as early as 1752 by Abbé Nicolas Louis de Lacaillé using a meridian circle. Since the early 20th Century, measures have been made with photographic plates. Robert Grant Aitken (December 31, 1864 – October 29, 1951) was an American astronomer. ... Map of Pondicherry Region, Union Territory of Pondicherry, India Pondicherry (Tamil:புதுவை,Hindi: पॉण्डिचेरी) is a Union Territory of India. ... Astrometry is a part of Astronomy and deals with the positions of stars and other celestial bodies, their distances and movements. ... Abbé Nicolas Louis de Lacaille (March 15, 1713 – March 21, 1762) was a French astronomer. ... Please wikify (format) this article as suggested in the Guide to layout and the Manual of Style. ...


By 1926, William Stephen Finsen produced the general orbit elements now accepted for this system. Future positions could then be calculated from a binary star ephemeris with sufficiently accuracy for visual observers. Others (e.g. the French astronomer D. Pourbaix in 2002) have slightly refined the orbital elements. (See the second Visual binary orbit in the Observational data side-box.) The established eighty-odd year orbital period for α Centauri AB is therefore reasonably accurate. William Stephen Finsen (July 28, 1905 – May 16, 1979) was a South African astronomer. ... The elements of an orbit are the parameters needed to specify that orbit uniquely, given a model of two ideal masses obeying the Newtonian laws of motion and the inverse-square law of gravitational attraction. ... An ephemeris (plural: ephemerides) (from the Greek word ephemeros = daily) is a device giving the positions of astronomical objects in the sky. ...

Alpha Centauri A and B resolved over the limb of Saturn, as seen by Cassini–Huygens.

Alpha Centauri is popularly known as the closest star system to our Solar System at about 4.37 light-years distant, or about 41.5 trillion kilometres, 25.8 trillion miles or 277,600 AU. This was discovered by Thomas Henderson, who made many exacting observations of both stars in the AB system. He obtained their trigonometric parallaxes (their tiny annual circular movements against the background stars) between April 1832 and May 1833, but did not release them because he seriously doubted his own results, feeling they were too large to be true. Henderson eventually published his results in 1839, after Friedrich Wilhelm Bessel had released his own accurately determined parallax for the star 61 Cygni in 1838. For this reason, Alpha Centauri is considered to be the second star to have its distance measured. Cassini–Huygens is a joint NASA/ESA/ASI unmanned space mission intended to study Saturn and its moons. ... This article is about the Solar System. ... A light-year, symbol ly, is the distance light travels in one year: exactly 9. ... Thomas James Henderson (December 28, 1798 – November 23, 1844) was an astronomer noted for being the first person to measure the distance to Alpha Centauri, the major component of the nearest stellar system to Earth, and for being the first Astronomer Royal for Scotland. ... For other uses, see Parallax (disambiguation). ... Friedrich Wilhelm Bessel (July 22, 1784 – March 17, 1846) was a German mathematician, astronomer, and systematizer of the Bessel functions (which, despite their name, were discovered by Daniel Bernoulli). ... 61 Cygni is a star in the constellation Cygnus. ...


Proxima Centauri was discovered by R.T.A. Innes in 1915 from South Africa, being detected by blinking two separate photographic plates taken at different times during one of his dedicated proper motion surveys. It showed very large proper motions similar in both size and direction to those of α Centauri AB, which suggested they were associated. It is usually regarded as part of the system, and presently in its orbit is slightly closer to us than α Centauri AB. Lying 4.22 light-years away, Proxima Centauri is thus celebrated as the closest star to the Sun. Most of the modern calculated distances for all three stars are derived from the parallaxes in the Hipparcos star catalog (HIP). Proxima Centauri (Latin proximus, -a, -um: meaning next to or nearest to)[4] is a red dwarf star that is likely a part of the Alpha Centauri star system and is the nearest star to the Sun at a distance of 4. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... Hipparcos (for High Precision Parallax Collecting Satellite) was an astrometry mission of the European Space Agency (ESA) dedicated to the measurement of stellar parallax and the proper motions of stars. ...


Alpha Centauri : The Gravitational System

Component Sizes and Colours. Shows the relative sizes and colours stars in the Alpha Centauri system and compares them to the Sun.
Component Sizes and Colours. Shows the relative sizes and colours stars in the Alpha Centauri system and compares them to the Sun.

Alpha Centauri is the collective name of this triple star system. It consists of two main stars, α Cen A and α Cen B, together often labelled as α Cen AB, which is the established binary star system. A third component, α Cen C is the much smaller and dimmer red dwarf star named Proxima Centauri. Download high resolution version (3770x1368, 56 KB) File links The following pages link to this file: Alpha Centauri User:Dbenbenn/gallery ... Download high resolution version (3770x1368, 56 KB) File links The following pages link to this file: Alpha Centauri User:Dbenbenn/gallery ... For the band, see Binary Star (band). ... This article is about the type of star. ... Proxima Centauri (Latin proximus, -a, -um: meaning next to or nearest to)[4] is a red dwarf star that is likely a part of the Alpha Centauri star system and is the nearest star to the Sun at a distance of 4. ...


The designation as "AB" has important significance for binary stars. In double star astronomy, and in most astronomical references, this suggests the central gravitational point of the binary relative to companion star(s) in multiple systems.[7] "AB-C" usage refers to the orbit of Proxima around the central binary, being the distance between the centre of gravity and the outlying companion. Sometimes older references use A×B, but this usage has been discontinued for decades. Since the distance from the Sun to α Cen AB does not differ significantly from that to either star in the binary system, it makes sense to refer to the binary as a solitary object. A binary star system consists of two stars both orbiting around their barycenter. ...


These binary components and Proxima Centauri are described individually as follows;


Alpha Centauri AB

Apparent and True Orbits of Alpha Centauri. Motion is shown from the A component against the relative orbital motion of B component. The Apparent Orbit (thin ellipse) is the shape of the orbit as seen by the observer on Earth. The True Orbit is the shape of the orbit viewed perpendicular to the plane of the orbital motion.
Apparent and True Orbits of Alpha Centauri. Motion is shown from the A component against the relative orbital motion of B component. The Apparent Orbit (thin ellipse) is the shape of the orbit as seen by the observer on Earth. The True Orbit is the shape of the orbit viewed perpendicular to the plane of the orbital motion.

Alpha Centauri A is the principal member or primary of the binary system, being both slightly larger and more luminous than our Sun. Like the Sun, it is a main sequence star with a similar yellowish-white colour, whose stellar classification is spectral type G2 V. From the determined mutual orbital parameters, Alpha Centauri A is about 10% more massive than our Sun, with a radius about 23% larger.[3] Image File history File links Generated by author/contributor. ... Image File history File links Generated by author/contributor. ... Sol redirects here. ... Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ...


Alpha Centauri B is the companion star or secondary to the primary star, appearing slightly smaller and less luminous than the Sun. This main sequence star displays the spectral type of K1 V, being an observed deeper orangish-yellow colour than the primary star. By mass, α Cen B is about 90% of the Sun, and is 14% smaller in radius.[3] A likely solar-like rotation period of some 36.8 days has been determined.[8] Although it has a lower luminosity than component A, star B emits a higher level of energy in the X-ray part of the spectrum. The light curve of B varies on a short time scale and at least one flare has been observed.[9] Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...


The stars revolve about each other in a moderately elliptical (e = 0.5179) 79.91-year-long orbit.[10] Unlike most of the planetary orbits in the Solar System, these stars can approach to 11.2 astronomical units (1.67 billion kilometres - roughly the distance between the Sun and Saturn) of each other, or can recede to a separation of 35.6 AU (5.9 billion kilometres, or approximately the distance from the Sun to Pluto). [1] From this one can calculate the total mass (ΣMʘ) of both stars to be about twice that of the Sun ([(11.2 + 35.6) / 2]3 / 79.912 = 2.0, see formula). Both these stars, according to stellar evolution theory, are slightly older than the Sun[3]; some sources quote 5 to 6 billion years (as implied by their derived mass and spectral characteristics). In astrodynamics, under standard assumptions any orbit must be of conic section shape. ... The astronomical unit (AU or au or a. ... This article is about the planet. ... Atmospheric characteristics Atmospheric pressure 0. ... In astrodynamics, the standard gravitational parameter () of a celestial body is the product of the gravitational constant () and the mass : The units of the standard gravitational parameter are km3s-2 Small body orbiting a central body Under standard assumptions in astrodynamics we have: where: is the mass of the orbiting... Projected timeline of the Suns life In astronomy, stellar evolution is the process by which a star undergoes a sequence of radical changes during its lifetime. ...


In their true orbit, both stars last made their closest approach (periastron) of 11.5 A.U. in August 1955; this will not occur again until May 2035. Apastron, when the stars are furthest apart in the orbit at 35.6 A.U., last occurred in May 1995. The two stars are presently approaching each other. The next apastron will be in A.D. 2075. [10] A diagram of Keplerian orbital elements. ... Year 1955 (MCMLV) was a common year starting on Saturday (link displays the 1955 Gregorian calendar). ... 2035 (MMXXXV) will be a common year starting on Monday of the Gregorian Calendar. ... A diagram of Keplerian orbital elements. ... Year 1995 (MCMXCV) was a common year starting on Sunday. ... Centuries: 20th century - 21st century - 22nd century Decades: 2020s 2030s 2040s 2050s 2060s - 2070s - 2080s 2090s 2100s 2110s 2120s Years: 2071 2072 2073 2074 2075 - 2076 - 2077 2078 2079 2080 2081 Events The one hundrieth anniversary of the Watergate Scandal court verdicts will occur in January 2075 Categories: 21st century...


As seen from the Earth, the apparent orbit of this binary star means that the separation and position angle are in continuous change throughout the projected eighty-odd year period. According to the current version of the U.S.N.O.'s 6th Binary Star Catalogue : Ephemeris, the observed distance between the stars is now 8.29 arcsec through P.A. 237 degrees (2008) reducing in the next year to 7.53 arcsec through P.A. 241 degrees (2009). The next apparent closest approach of both these stars will be seen during February 2016, when the distance reduces to 4.0 arcsec through P.A. 300 degrees. (See External Reference. ) The maximum separation of these stars is about 22 arcsec, which last happened in February 1976. This will not occur again until January 2056. Separation may refer to a several different subjects: In chemistry, separation refers to the separation process. ... Position angle, usually abbreviated PA, is a measurement derived from observing visual binary stars. ... Aerial view of USNO. The United States Naval Observatory (USNO) is one of the oldest scientific agencies in the United States. ... Arcsec is an abbreviation for either: arcsecond or arcsecant. ... Look up Pa in Wiktionary, the free dictionary Pa, PA or pa may stand for: pa, a word for dad or father (pa or paw) pa, Chinese political title meaning hegemon Pa, Maori word meaning a fortified village or redoubt, described at length in Maori Wars Per annum, p. ... Arcsec is an abbreviation for either: arcsecond or arcsecant. ... Look up Pa in Wiktionary, the free dictionary Pa, PA or pa may stand for: pa, a word for dad or father (pa or paw) pa, Chinese political title meaning hegemon Pa, Maori word meaning a fortified village or redoubt, described at length in Maori Wars Per annum, p. ... 2016 (MMXVI) will be a leap year starting on Friday of the Gregorian calendar. ... Arcsec is an abbreviation for either: arcsecond or arcsecant. ... Arcsec is an abbreviation for either: arcsecond or arcsecant. ... Year 1976 (MCMLXXVI) was a leap year starting on Thursday (link will display full calendar) of the Gregorian calendar. ... MMLVI in Roman Numerals. ...


Alpha Centauri C / Proxima Centauri / V645 Centauri

Main article: Proxima Centauri

The much fainter red dwarf star named Alpha Centauri C, "α Cen C", Proxima Centauri, or simply "Proxima", is about 13,000 A.U. away from Alpha Centauri AB (1.94 trillion kilometres or 0.21 ly – about one-twentieth the distance between Alpha Centauri AB and the Sun). It may be in orbit around it, though the period must be in the order of 100,000 to 500,000 years or more. It is possible that the orbit might be hyperbolic, similar to the planetary sling-shot effect adopted by interplanetary spacecraft to change direction and velocity to a second planetary body, and so Proxima may leave the system after a few million years. Association with Alpha Centauri AB is unlikely to be entirely accidental, as it shares approximately the same motion through space as the inner binary star system. However, true gravitational binding is yet to be proven. Proxima Centauri (Latin proximus, -a, -um: meaning next to or nearest to)[4] is a red dwarf star that is likely a part of the Alpha Centauri star system and is the nearest star to the Sun at a distance of 4. ... This article is about the type of star. ... The astronomical unit (AU or au or a. ... A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one year. ... In astrodynamics or celestial mechanics a hyperbolic trajectory is an orbit with the eccentricity greater than 1. ...


Seen from Earth, Proxima Centauri is 2.2 degrees south-west from Alpha Centauri AB. This is about four times the angular diameter of the Full Moon, and almost exactly half the distance between Alpha Centauri and Beta Centauri. A moderate-sized telescope is required to see Proxima. The angular diameter of an object as seen from a given position is the diameter measured as an angle. ...


Proxima usually appears as a 13.1 visual magnitude deep-red star in a poor star field of only several stars. The star is listed in the General Catalogue of Variable Stars (G.C.V.S. Version 4.2) as V645 Cen, being a known UV Ceti-type flare star, which may suddenly and unexpectedly brighten by about two magnitudes or so. (A visual magnitude of 11.0 is often quoted.) Both amateur and professional astronomers monitor this star from time to time - with both optical and radio telescopes. Proxima is of spectral class M5Ve or M5VIe, whose B-V colour index is +1.81. The spectral class suggest this is either a small main sequence star (Type V) or sub-dwarf (VI) with emission lines. Its mass is about 0.4 solar masses. In science, a magnitude is the numerical size of something: see orders of magnitude. ... Luyten 726-8 is a binary star system that is one of Earths nearest neighbors. ... A flare star is a variable star which can undergo unpredictable dramatic increases in brightness for a few minutes or a few hours. ... In astronomy one method of classifying stars is through the analysis of their absorption spectra, by this method stars are assigned a spectral class. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ... A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ...


The closest stars to the Alpha Centauri system are the Sun and Barnard's star (1.98 pc or 6.47 ly). From Earth, Barnard's star is currently 5.96 ly. away. Barnards Star is a very low-mass star in the constellation Ophiuchus which was discovered by the astronomer E. E. Barnard in 1916. ... A parsec is the distance from the Earth to an astronomical object which has a parallax angle of one arcsecond. ...


Alpha Centauri: A High Proper Motion System

Apparent motion of Alpha Centauri relative to Beta Centauri.
Apparent motion of Alpha Centauri relative to Beta Centauri.

Alpha Centauri, like the first magnitude stars of Sirius and Arcturus, shows high proper motions against the background sky, which causes its sky position to gradually change over the centuries. These slow motions were unknown to ancient astronomers, like Aristotle, who stated that all stars were permanently fixed to their places on the celestial sphere. Edmond Halley in 1718 first found that contemporary astrometric sky positions, especially of the bright star Arcturus, differed significantly from those given by Ptolemy (probably measured earlier by Hipparchos) during the 1st Century B.C. (In Arcturus' case, the star moved almost ½ degree in 1800 years.) These motions were found mainly for northern stars, and thus the motion of the southern star Alpha Centauri was not found until the early 17th Century. Image File history File links Motion-of-Alpha-Cen. ... Image File history File links Motion-of-Alpha-Cen. ... Beta Centauri (β Cen / β Centauri), also known as Hadar or Agena, is the second brightest star in the constellation Centaurus and the eleventh brightest star in the nighttime sky. ... This article is about the brightest star in the night sky of Earth. ... For other uses, see Arcturus (disambiguation). ... For other uses, see Aristotle (disambiguation). ... The celestial sphere is divided by the celestial equator. ... Edmond Halley FRS (IPA: ) (November 8, 1656 – January 14, 1742) was an English astronomer, geophysicist, mathematician, meteorologist, and physicist. ... Year 1718 (MDCCXVIII) was a common year starting on Saturday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Tuesday of the 11-day slower Julian calendar). ... Astrometry is a part of Astronomy and deals with the positions of stars and other celestial bodies, their distances and movements. ... This article is about the geographer, mathematician and astronomer Ptolemy. ... For the Athenian tyrant, see Hipparchus (son of Pisistratus). ...


As stated above, Thomas Henderson in the 1830s was the first to discover Alpha Centauri's true distance, but also soon realised that this system was likely to have a high proper motion. Because of the proximity of these stars, their true velocity through space would appear to be much larger. In Alpha Centauri's case, the apparent motion of these stars were found from the astrometric observations made by Abbé Nicolas Louis de Lacaille during 1751-52. Thomas Henderson (December 28, 1798 – November 23, 1844) was an astronomer noted for being the first person to measure the distance to Alpha Centauri, the major component of the nearest stellar system to Earth, and for being the first Astronomer Royal of Scotland. ... Abbé Nicolas-Louis de Lacaille (March 15, 1713–March 21, 1762) was a French astronomer. ...


Using the Hipparcos Star Catalogue (HIP) data, the mean individual proper motions (in milli arcsec) are -3678 mas.yr-1 (mas/yr) or 3.678 arcsec per year in right ascension (the negative value indicating the sky motion is east to west) and +481.84 mas.yr-1 (mas/yr) or 0.48184 arcsec per year in declination. As proper motions are cumulative, the motion of Alpha Centauri is about 6.1 arcmin/century (367.8 arcsec/ century) equivalent to 1.02 degrees/millennia or 61.3 arcmin/millennia. These motions are about one-fifth and twice, respectively, the diameter of the full moon. The Hipparcos and Tycho Catalogues (Tycho-1) are the primary products of the European Space Agencys astrometric mission, Hipparcos. ... Arcsec is an abbreviation for either: arcsecond or arcsecant. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... A century (From the Latin cent, one hundred) is one hundred consecutive years. ... This article describes the unit of angle. ... These pages contain the trends of millennia and centuries. ... These pages contain the trends of millennia and centuries. ... This article is about Earths moon. ...


A rough calculation, for example, shows that the current distance of 4.4 degrees between Alpha and Beta Centauri will take about 4200 years by proper motion to cross, therefore these two naked-eye stars will be closest in about A.D. 6200. Calculating backwards in time, say to the time of 2000 years ago, the pointers of Alpha and Beta Centauri were about 6½ degrees apart, and Alpha Centauri was instead lying in the present day southern constellation of Circinus. Circinus, Latin for Compass, is one of the small southern (declination −50 to −60 degrees) constellations. ...


A more precise calculation can be made that involves taking into account the slight changes in the distance of the star by its own motion, and in Alpha Centauri's case, this means a slow increase in the values of these proper motions. Slight variances are also due to the small difference in measured values of the proper motions of α Cen A and α Cen B, which is roughly about 0.5% in accuracy.


Future Sky Positions of Alpha Centauri

Around A.D. 5973 (or as sometimes expressed 5973 C.E), the significantly very high proper motions observed for the stars of Alpha Centauri will eventually lead to some future observer seeing a brilliant naked-eye visual double star adjoining the slightly fainter 1st magnitude star Beta Centauri / β Centauri. At closest approach, the apparent separation of these stars will be only 23 arcmin or two-thirds the Moon's apparent diameter.[citation needed] [11] This spectacular duo will form a very rare optical stellar conjunction. Comparing to the large general motion of α Centauri, β Centauri is roughly one-hundredth its overall motion. (β Centauri's proper motions being -33.96 mas.yr-1 in R.A. and -2.506 mas.yr-1 in Dec., respectively.) As such, β Centauri appears almost stationary over the centuries or millennia in its general position against the background stars. This difference in proper motion is primarily caused by β Centauri lying just over 120 times farther away from us than Alpha Centauri itself. (530 light-years compared to 4.3 light-years). So it is really the overall large apparent motion α Centauri that has formed this future optical alignment, making the stars more akin to slowly passing one another as two ships in the night. AD redirects here. ... BCE redirects here. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... When two stars are so nearly in the same direction as seen from Earth that they appear to be a single star to the naked eye but may be separated by the use of telescopes, they are referred to as a double star. ... Beta Centauri (β Cen / β Centauri), also known as Hadar or Agena, is the second brightest star in the constellation Centaurus and the eleventh brightest star in the nighttime sky. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ...


After this, Alpha Centauri will continue to slowly brighten, passing just north of the Southern Cross or Crux, before moving northwest and up towards the celestial equator and away from the galactic plane. By about 29,700 A.D., α Centauri will lie exactly 1.00 parsecs or 3.26 light-years away, reaching the maximum brightness of -0.86 visual magnitude - similar in brightness to present day Canopus. At this time it will be placed near the present-day constellation of Hydra. Soon after this relatively close solar approach, the system will then begin to move away from the Sun. In 43,300 A.D., α Centauri will pass near 2nd magnitude Alpha Hydrae / Alphard. Then the apparent visual magnitude will be +1.03 and lie 5.36 ly. away. [12] Southern Cross is the English name of Crux Australis, a constellation visible in the Southern Hemisphere. ... CRUX is a lightweight, i686-optimized Linux distribution targeted at experienced Linux users. ... The celestial equator is a great circle on the imaginary celestial sphere, which could be constructed by inflating the Earths equator until it intersects with said sphere. ... The galactic plane is the plane in which the majority of a flattened galaxys mass lies. ... A parsec is the distance from the Earth to an astronomical object which has a parallax angle of one arcsecond. ... This article does not cite any references or sources. ... HYDRA is a fictional terrorist organization in the Marvel Universe. ... Alphard (α Hya / α Hydrae / Alpha Hydrae) is the brightest star in the constellation Hydra. ...


As the star slowly disappears among the stars of the Milky Way, it will reach a final vanishing point location, due to visual perspective, more than 100,000 years from now. Here this once bright star will finally drop below naked-eye visibility somewhere in the faint southern constellation of Telescopium. This unusual location results from α Centauri's independent galactic motion being highly tilted with respect to the plane of our Milky Way galaxy. For other uses, see Vanishing point (disambiguation). ... Look up perspective in Wiktionary, the free dictionary. ... Telescopium (Latin for Telescope) is a minor southern constellation identified and named by Nicolas Louis de Lacaille, the 18th century French astronomer, a student of the southern skies. ... For other uses, see Milky Way (disambiguation). ...


The Sky from Alpha Centauri

Looking toward Sol from Alpha Centauri in Celestia
Looking toward Sol from Alpha Centauri in Celestia

Viewed from near the Alpha Centauri system, the sky would appear very much as it does to observers on Earth, except being without the three stars of α Centauri. Most of the familiar constellations, such as Ursa Major and Orion, would appear almost unchanged. However, Centaurus would be missing its brightest star, and our Sun would appear as star of +0.5 magnitude in the northern Milky Way constellation of Cassiopeia. An interstellar observer would find the familiar // shape of Cassiopeia becoming a ///, with the Sun being at the end closest to the star ε Cassiopeiae. The Sun's position is easily plotted, as it lies at the point antipodal to Alpha Centauri's current position as seen from Earth. This is at RA 02h 39m 35s, Dec. +60° 50' (2000) Image File history File links Download high-resolution version (1183x937, 64 KB) A view of the sky towards our home star, Sol, as seen from the vicinity of Alpha Centauri A. Our sun would be in the constellation Cassiopeia or Perseus as viewed from there. ... Image File history File links Download high-resolution version (1183x937, 64 KB) A view of the sky towards our home star, Sol, as seen from the vicinity of Alpha Centauri A. Our sun would be in the constellation Cassiopeia or Perseus as viewed from there. ... Sol redirects here. ... For other uses, see Celestia (disambiguation). ... This article is about the constellation. ... For other uses, see Orion. ... Sol redirects here. ... Cassiopeia (pronounced , colloquially ) is a northern constellation which Greek mythology considered to represent the vain queen Cassiopeia who boasted about her unrivaled beauty. ... Epsilon Cassiopeiae (ε Cas / ε Cassiopeiae) is a star system in the constellation Cassiopeia. ... In mathematics, the antipodal point of a point on the surface of a sphere is the point which is diametrically opposite it — so situated that a line drawn from the one to the other passes through the centre of the sphere and forms a true diameter. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ...


From Alpha Centauri, the bright stars which are relatively close to us, such as Sirius, Procyon and Altair, would appear to have quite different sky positions. Sirius, for example, would been seen to become part of the constellation of Orion, appearing some 2 degrees west of Betelgeuse. It would also be -1.2 magnitude star - some 0.2 magnitudes dimmer than seen from Earth. Other bright stars like Fomalhaut and Vega, although slightly further away, would appear only slightly displaced from their familiar positions in the sky. This article is about the brightest star in the night sky of Earth. ... Procyon (α CMi / α Canis Minoris / Alpha Canis Minoris) is the brightest star in the constellation Canis Minor and the eighth brightest star in the nighttime sky. ... Altair (α Aql / α Aquilae / Alpha Aquilae / Atair ) is the brightest star in the constellation Aquila and the twelfth brightest star in the nighttime sky, at visual magnitude 0. ... This article is about the star. ... This article is about the star. ... For other uses, see Vega (disambiguation). ...


Due to the low luminosity of Proxima Centauri, to the naked-eye it would remain an inconspicuous 4.5 magnitude star even though being merely 0.25 light-year away. Its slow and gradual movement against the stars of the background sky would probably be detectable to the average person over one or two decades. A light-year, symbol ly, is the distance light travels in one year: exactly 9. ...


From Proxima itself, α Centauri AB would appear like two close very bright stars with the combined magnitude of −6.80. Depending on the position of the binary in their orbit, the stars would appear noticeably double to the naked eye or occasionally, for a short time, as one unresolved star. In visual magnitude, α Cen A would be −6.52, and α Cen B −5.19. The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ...


Does Alpha Centauri Have Planets?

Discovery of additional planets orbiting both single stars and binary star systems, leaves the real possibility of finding either new planets in the Alpha Centauri AB system or planets revolving close to either α Cen A or α Cen B. With additional evidence, like both the principle stars being similar in nature to the Sun, I.e. high metallicity and similar ages, simply reinforces the astronomers view that it is very worthwhile to make detailed searches for planetary bodies around Alpha Centauri. Additionally, planets have also been found in other similar binary systems. I.e. Gamma Cephei. Several established planet-hunting teams have used various radial velocity or star transit methods in their searches around these two bright stars. All have so far all have failed to find any suggestion of any brown dwarfs, gas giants (planets) or small extrasolar terrestrial planets. The globular cluster M80. ... Gamma Cephei (γ Cep / γ Cephei) is a star in the constellation Cepheus. ... Radial velocity is the velocity of an object in the direction of the line of sight. ... 2003 Transit of Mercury The term transit or astronomical transit has two meanings in astronomy: A transit is the astronomical event that occurs when one celestial body appears to move across the face of another celestial body, as seen by an observer at some particular vantage point. ... This brown dwarf (smaller object) orbits the star Gliese 229, which is located in the constellation Lepus about 19 light years from Earth. ... This article is about the rock band. ... A terrestrial planet or telluric planet is a planet which is primarily composed of silicate rocks. ...


Based on theoretical computer simulations, other planetary astronomers consider that any potential terrestrial planets that did once orbit near the stars' habitable zones are now likely no longer located there. The loss several billion years ago of these small bodies probably happened during the system's formation. All may have since been ejected by significant disruptions caused by strong gravitational or perturbation effects generated between the two main stellar components. Look up perturbation in Wiktionary, the free dictionary. ...


In the not too distant future, assuming our human technology advances enough to enable voyages for interstellar robotic probes, Alpha Centauri may be first on the list for exo-planetary exploration. Such lengthy trips to cross the huge empty gulfs between the stars would likely still take several centuries, and this still assumes that some interstellar spacecraft could obtain high enough velocities to get there. If present ground or orbit based observatories are unable to detect planets, future unmanned exploratory journeys will be the only means of obtaining direct evidence that such planets do exist.


Alpha Centauri From a Hypothetical Planet

Any hypothetical planet orbiting around either α Centauri A or α Centauri B would see the other star as an intensely bright star in the sky with a discernible disk. For example, an Earth-like planet about 1.25 Astronomical Unit (A.U.) from α Cen A (with an orbital period of about one year three months or 1.3(4) a) would get Sun-like illumination from its primary, where α Cen B would appear 5.7 to 8.6 magnitudes dimmer (−21.0 to −18.2), 190 to 2700 times dimmer than α Cen A but still 170 to 2300 times brighter than the full moon. Conversely, a similar Earth-like planet at 0.71 A.U. from α Cen B (with the revolution period of about 0.6(3) a) would get Sun-like illumination from its primary, where α Cen A would appear 4.6 to 7.3 magnitudes dimmer (−22.1 to −19.4), 70 to 840 times dimmer than α Cen B but still 520 to 6300 times brighter than the full moon. In both these cases, in the course of the planet's year, the secondary sun would appear to circle the whole sky. Either way, any such hypothetical Earth-like planet would find that the secondary sun would not be bright enough to significantly influence climate or plant photosynthesis. The astronomical unit (AU or au or a. ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... This article is about Earths moon. ... A year (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Photosynthesis splits water to liberate O2 and fixes CO2 into sugar The leaf is the primary site of photosynthesis in plants. ...


If one assumes the planet has a low orbital inclination with respect to the mutual orbit of α Cen A and B, then the secondary star would start beside the primary at conjunction. Half a period (about forty years) later, at opposition, both stars would be opposite each other in the sky. At this time, for about half the planetary year the appearance of the night sky would be dark blue - similar to our sky during a total solar eclipse. People could easily walk around and clearly see the surrounding terrain. Even reading a book would be quite possible without any artificial light. After another half period in the stellar orbit, the stars would complete the cycle and return to conjunction. At this time an Earth-like day and night cycle would return. Opposition is a term used in positional astronomy and astrology to indicate when one celestial body is on the opposite side of the sky when viewed from a particular place (usually the Earth). ... Photo taken during the 1999 eclipse. ...


Possibilities In Planet Formation

Some recent computer models regarding planetary formation, do predict the possibility of terrestrial planets existing around both Alpha Centauri A and B [13][14][15]. Some other models also strongly suggested that formation of gas giant planets similar to our Jupiter and Saturn remain unlikely because of the significant gravitational and angular momentum effects of this binary system.[16] Given the similarities to the Sun in star type, age and probable stability of the orbits, it has been sometimes suggested that this stellar system could hold one of the best possibilities for extraterrestrial life.[17] Although highly speculative, both these stars are of the right spectral type to possibly harbour life on some potential planet. [18][19][20] The inner planets, Mercury, Venus, Earth, and Mars, their sizes to scale. ... This article does not cite any references or sources. ... For other uses, see Jupiter (disambiguation). ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... Green people redirects here. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ...


However, some astronomers have speculated that any possible terrestrial planets in the Alpha Centauri system may be bone dry or lack significant atmospheres. This is because theoretically, both Jupiter and Saturn were very crucial in perturbing comets into the inner solar system, thus providing the inner planets with their own source of water and various other ices. This significant issue might not be as problematic, if for example, α Centauri B happened to have played a similar role as any hypothetical giant gas planets orbiting α Centauri A. (or conversely, α Cen A for α Cen B.) Also against this view is that most comets are considered to reside in the outer regions of the stellar system in some huge Oort Cloud, and these comets can only sent sun-wards by the perturbations of gas planets or disruptions by the passing of nearby stars. As yet there is no direct evidence that such regions do exist around α Centauri AB, and it is indeed possible that this theoretical Oort Cloud region was totally destroyed during the system's own formation. Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Artists rendering of the Oort cloud and the Kuiper Belt. ...


Any suspected Earth-like planet around Alpha Centauri A would have to be placed about 1.25 AU away - about halfway between the distances of Earth's orbit and Mars' orbit in our own Solar System, so as to have similar planetary temperatures and conditions for liquid water to exist. For the slightly less luminous and cooler Alpha Centauri B, this distance would be closer to its star at about 0.7 AU, being about the distance that Venus is from the Sun. The astronomical unit (AU or au or a. ... This article is about Earth as a planet. ... This article is about the planet. ... This article is about the Solar System. ... The astronomical unit (AU or au or a. ... This article is about the planet. ... Sol redirects here. ...


To find evidence of such planets, currently both Proxima Centauri and α Centauri AB are among the listed "Tier 1" target stars for NASA's Space Interferometry Mission (SIM). SIM is designed to be able to detect planets as small as three Earth-masses or smaller within two Astronomical Units of a "Tier 1" target.[21] For other uses, see NASA (disambiguation). ... Artists concept of Space Interferometry Mission spacecraft The Space Interferometry Mission (SIM), also called SIM PlanetQuest, is a NASA instrument originally expected to be launched in December of 2011; however due to budget cuts it will now launch no sooner than between October 2014 and April 2015. ... The astronomical unit (AU or au or a. ...


Origin of Name and Cultural Significance

The system bears the proper name Rigil Kentaurus[22] (often shortened to Rigil Kent.[23], former Rigjl Kentaurus[24][25], and Riguel Kentaurus[26] in Portuguese), derived from the Arabic phrase Rijl Qantūris[23] (or Rijl al-Qantūris,[27] meaning "Foot of the Centaur)," but is most often referred to by its Bayer designation Alpha Centauri. An alternative name is Toliman, whose etymology may be Arabic al-Zulmān (meaning "the Ostriches")[23], or Hebrew (meaning "The Heretofore and the Hereafter" and/or "Shoot of the Vine").[citation needed] (See Centaurus) Finally, it is sometimes called Bungula[28], possibly coined from "β" and the Latin ungula (meaning "hoof").[23] This latter name in modern times is, however, rarely used. Arabic redirects here. ... Centaurus (Latin for centaur) was one of the 48 constellations listed by Ptolemy, and counts also among the 88 modern constellations. ... The tone or style of this article or section may not be appropriate for Wikipedia. ... Hebrew redirects here. ... Centaurus (Latin for centaur) was one of the 48 constellations listed by Ptolemy, and counts also among the 88 modern constellations. ... For other uses, see Latins and Latin (disambiguation). ...


In Chinese, Alpha Centauri was called Nánmén'èr (南門二) "Second Star of the Southern Gate". As mentioned, Alpha and Beta Centauri together form the "Southern Pointers" to Crux, the Southern Cross. CRUX is a lightweight, i686-optimized Linux distribution targeted at experienced Linux users. ...


Alpha Centauri in Modern Fiction

Alpha Centauri's relative proximity makes it in some ways likely the logical choice as "first port of call". Speculative fiction about interstellar travel predicts eventual human exploration, and even the discovery and colonization of planetary systems. These themes are common to many works of science fiction and video games. Because of its status as our nearest galactic neighbor, Alpha Centauri has frequently been used in science fiction stories involving interstellar travel. This article or section does not cite its references or sources. ... Speculative fiction - Wikipedia, the free encyclopedia /**/ @import /skins-1. ... Artists depiction of a hypothetical Wormhole Induction Propelled Spacecraft, based loosely on the 1994 warp drive paper of Miguel Alcubierre. ... Space exploration is the use of astronomy and space technology to explore outer space. ... This article needs to be cleaned up to conform to a higher standard of quality. ... Artists conception of a space habitat called the Stanford torus, by Don Davis Space colonization (also called space settlement, space humanization, space habitation, etc. ... An artists concept of a planetary system A planetary system consists of the various non-stellar objects orbiting a star such as planets, moons, asteroids, meteoroids, comets, and cosmic dust. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Computer and video games redirects here. ... Science fiction is a form of speculative fiction principally dealing with the impact of imagined science and technology, or both, upon society and persons as individuals. ... Artists depiction of a hypothetical Wormhole Induction Propelled Spacecraft, based loosely on the 1994 warp drive paper of Miguel Alcubierre. ...


References

  1. ^ LHS 50 -- High proper-motion Star. Centre de Données astronomiques de Strasbourg. Retrieved on 2008-06-06.
  2. ^ LHS 51 -- High proper-motion Star. Centre de Données astronomiques de Strasbourg. Retrieved on 2008-06-06.
  3. ^ a b c d e f g h i Kervella, Pierre; Thevenin, Frederic (March 15, 2003). A Family Portrait of the Alpha Centauri System. ESO. Retrieved on 2008-06-06.
  4. ^ 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. Retrieved on 2007-06-01. 
  5. ^ Kervella, Pierre; Thévenin, Frédéric; Du Foresto, Vincent Coudé; Mignard, François (2007). "Deep imaging survey of the environment of Alpha Centauri - I. Adaptive optics imaging of Alpha Cen B with VLT-NACO". Astronomy and astrophysics 464 (1): 367–372. Retrieved on 2008-06-06. 
  6. ^ Pourbaix, D.; Nidever, D.; McCarthy, C.; Butler, R. P.; Tinney, C. G.; Marcy, G. W.; Jones, H. R. A.; Penny, A. J.; Carter, B. D.; Bouchy, F.;+ 6 more (2002). "Constraining the difference in convective blueshift between the components of alpha Centauri with precise radial velocities". Astronomy and Astrophysics 386 (1): 208–285. doi:10.1051/0004-6361:20020287. Retrieved on 2008-06-15. 
  7. ^ Heintz, W.D. (1978). Double Stars. D. Reidel Publishing Company, Dordrecht, 19. 
  8. ^ Guinan, E.; Messina, S.. "IAU Circular 6259, Alpha Centauri B", Central Bureau for Astronomical Telegrams. 
  9. ^ Robrade, J.; Schmitt, J.H.M.M., Favata, F. (2005). "X-rays from α Centauri - The darkening of the solar twin". Astronomy and Astrophysics 442 (1): 315–321. Retrieved on 2008-06-27. 
  10. ^ a b Hartkopf, W.; Mason, D. M.. "Sixth Catalog of Orbits of Visual Binaries", U.S.Naval Observatory, Washingto D.C.. 
  11. ^ Hartung, E.J.; Frew, David Malin, David. "Astronomical Objects for Southern Telescopes", Cambridge University Press. 
  12. ^ Matthews, R.A.J. (1994). "The Close Approach of Stars in the Solar Neighbourhood". Quarterly Journal of the Royal Astronomical Society 35: 1 – 8. 
  13. ^ Javiera Guedes, Terrestrial Planet Formation Around Alpha Cen B
  14. ^ see Lissauer and Quintana in references below
  15. ^ Javiera M. Guedes, Eugenio J. Rivera, Erica Davis, Gregory Laughlin, Elisa V. Quintana, Debra A. Fischer (to be published in 2008). Formation and Detectability of Terrestrial Planets Around Alpha Centauri B. Astrophysical Journal.
  16. ^ M. Barbier, F. Marzari, H. Scholl (2002). "Formation of terrestrial planets in close binary systems: The case of α Centauri A". Astronomy & Astrophysics 396: 219 – 224. doi:10.1051/0004-6361:20021357. 
  17. ^ P.A. Wiegert and M.J. Holman (1997). "The stability of planets in the Alpha Centauri system". The Astronomical Journal 113: 1445 – 1450. 
  18. ^ Lissauer, J. J., E. V. Quintana, J. E. Chambers, M. J. Duncan, and F. C. Adams. (2004). "Terrestrial Planet Formation in Binary Star Systems.". "Revista Mexicana de Astronomia y Astrofisica (Serie de Conferencias); First Astrophysics meeting of the Observatorio Astronomico Nacional: Gravitational Collapse: From Massive Stars to Planets"; 22: 99 – 103. 
  19. ^ Quintana, E. V.; Lissauer, J. J.; Chambers, J. E.; Duncan, M. J.; (2002). "Terrestrial Planet Formation in the Alpha Centauri System.". Astrophysical Journal 2: 982–996. doi:10.1086/341808. 
  20. ^ Quintana, E. V.; Lissauer, J. J.;. "Terrestrial Planet Formation in Binary Star Systems.". "Planets in Binary Star Systems.". 
  21. ^ "Planet Hunting by Numbers," (Press Release), NASA, Stars and Galaxies, Jet Propulsion Laboratory, 18 October 2006. Retrieved 24 April 2007.
  22. ^ Bailey, F., "The Catalogues of Ptolemy, Ulugh Beigh, Tycho Brahe, Halley, and Hevelius," Memoirs of Royal Astronomical Society, vol. XIII, London, 1843.
  23. ^ a b c d Kunitzsch P., & Smart, T., A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations, Cambride, Sky Pub. Corp., 2006, p. 27
  24. ^ Hyde T., "Ulugh Beighi Tabulae Stellarum Fixarum", Tabulae Long. ac Lat. Stellarum Fixarum ex Observatione Ulugh Beighi, Oxford, 1665, p. 142.
  25. ^ Hyde T., "In Ulugh Beighi Tabulae Stellarum Fixarum Commentarii", op. cit., p. 67.
  26. ^ da Silva Oliveira, R., "Crux Australis: o Cruzeiro do Sul", Artigos: Planetario Movel Inflavel AsterDomus.
  27. ^ Davis Jr., G. A., "The Pronunciations, Derivations, and Meanings of a Selected List of Star Names,"Popular Astronomy, Vol. LII, No. 3, Oct. 1944, p. 16.
  28. ^ Burritt, E. H., Atlas, Designed to Illustrate the Geography of the Heavens, (New Edition), New York, F. J. Huntington and Co., 1835, pl. VII.

2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... is the 74th day of the year (75th in leap years) in the Gregorian calendar. ... Year 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 152nd day of the year (153rd in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 157th day of the year (158th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 166th day of the year (167th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 178th day of the year (179th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A news release or press release is a written or recorded communication directed at members of the news media for the purpose of announcing something claimed as having news value. ... is the 291st day of the year (292nd in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 114th day of the year (115th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... Thomas Hyde (1636 - 1703) was an English orientalist. ... A Star Atlas is a variant of the traditional geographic atlas, ie. ...

External links

External Links : Hypothetical Planets or Exploration

  • A Family Portrait of the Alpha Centauri System. SpaceRef.com. Retrieved on 21 March, 2003.
  • Alpha Centauri article at Memory Alpha, a Star Trek wiki
  • Alpha Centauri System
  • O Sistema Alpha Centauri (portuguese)
  • Alpha Centauri - Associação de Astronomia (portuguese)
  • http://www.space.com/scienceastronomy/080307-another-earth.html

This article is about the website. ... This article is about the entire Star Trek franchise. ... Wiki wiki redirects here. ...

See Also

This list of the nearest stars to Earth is ordered by increasing distance out to a maximum of 5 parsecs (16. ... Bright stars can be bright because they produce more light, because they are closer to us, or both. ... Project Longshot is a design for an interstellar spaceship, an unmanned probe intended to fly to Alpha Centauri powered by nuclear pulse propulsion. ...


  Results from FactBites:
 
Alpha Centauri - MSN Encarta (371 words)
Alpha Centauri C is also called Proxima Centauri; in the current portion of its orbit it is the closest star to the solar system, at a distance of 4.2 light-years.
Alpha Centauri A is a yellow star, slightly larger and brighter than the Sun, of spectral type G2 and apparent magnitude +0.01.
Alpha Centauri B is a yellow-orange star somewhat smaller and cooler than the Sun of spectral type K1 and apparent magnitude +1.34.
Alpha Centauri - Wikipedia, the free encyclopedia (2056 words)
It and Beta Centauri (which is close to Alpha Centauri in angular distance as seen from the Earth, but is actually many light-years away) are the "Pointers" to the Southern Cross.
Alpha and Beta Centauri are the second closest pair of first magnitude stars as seen from the Earth, and due to the effects of proper motion, they will become the closest pair in around 2166, overtaking Acrux and Becrux.
In Frank Herbert's Dune universe, the planet Ecaz is the fourth planet that orbits Alpha Centauri B. Ecaz is ruled by the feudal noble family of House Ecaz, and is known for its famous fogwood.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m