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Encyclopedia > 61 Cygni
61 Cygni A/B
Observation data
Epoch J2000
Constellation Cygnus
Right ascension 21h 06m 54.0/55.3s
Declination +38° 44' 57"/31"
Apparent magnitude (V) 5.20/6.05
Characteristics
Spectral type K5 V/K7 V
B-V color index 1.17/1.36
U-B color index 1.11/1.23
Variable type Suspected
Astrometry
Radial velocity (Rv) -65.0/-64.1 km/s
Proper motion (μ) RA: 4.155/4.107"/yr
Dec.: 3.259/3.144"/yr
Parallax (π) 0.28604" ± 0.00056"
Distance 11.40 ly (3.496 pc)
Absolute magnitude (MV) 7.48/8.33
Details
Mass 0.70/0.63 M
Radius 0.72/0.67 R
Luminosity 0.085/0.039 L
Temperature 4,450/4,120 K
Metallicity 79/79% Sun
Rotation period
Age >4.6 × 109 years
Visual binary orbit
Companion 61 Cygni B
Period (P) 653.2 years
Semimajor axis (a) 24.4"
Eccentricity (e) 0.40
Inclination (i) 51.85°
Node (Ω) 172.3°
Periastron epoch (T) 1689.7
Other designations
61 Cyg A/B, HD 201091/201092 HR 8085/8086 BD +38°4343/4344 GCTP 5077.00 A/B, GJ 820 A/B, LHS 62/63, Struve 2758 A/B, ADS 14636 A/B, and HIP 104214/104217.

61 Cygni is a star in the constellation Cygnus. Though it is among the least conspicuous of stars visible in the night sky to an observer without an optical instrument, 61 Cygni attracted the attention of astronomers due to its large proper motion. The star is in fact a double star system. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... -1... For the software company, see Cygnus Solutions. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... 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. ... 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. ... In astronomy, color index is a simple numerical expression that determines the color of an object. ... In astronomy, color index is a simple numerical expression that determines the color of an object. ... Most stars are of nearly constant luminosity. ... Astrometry is a part of astronomy and deals with the positions of stars and other celestial bodies, their distances and movements. ... 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 year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Parallax (Greek: παραλλαγή (parallagé) = alteration) is the change of angular position of two stationary points relative to each other as seen by an observer, due to the motion of said observer. ... The distance between two points is the length of a straight line segment between them. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standardized distance away. ... Mass is a property of physical objects that, roughly speaking, measures the amount of matter they contain. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... RADIUS (Remote Authentication Dial In User Service) is an AAA (authentication, authorization and accounting) protocol for applications such as network access or IP mobility. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... // In General Physics In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given direction. ... 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. ... Temperature is the physical property of a system which underlies the common notions of hot and cold; the material with the higher temperature is said to be hotter. ... The title of this article is incorrect due to technical limitations. ... In astronomy, the metallicity of an object is the proportion of its matter made up of elements other than hydrogen and helium. ... In astronomy, a rotation period is the time an astronomical object takes to complete one revolution around its rotation axis. ... Look up Age on Wiktionary, the free dictionary Age may refer to: The length of time that a person has lived, reckoned from date of birth in most cultures; see also: ageing, for the social, cultural, and economic factors of age and ageing. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A binary star system consists of two stars both orbiting around their barycenter. ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... 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. ... Inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit and is the angular distance of the orbital plane from the plane of the reference (usually planets equator or the ecliptic), stated in degrees. ... The term node can refer to: Node, a spatial locus along a standing wave where the wave has minimal amplitude. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... The word epoch can mean either an interval of time, or a particular point in time used as a reference point. ... 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. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Pleiades star cluster A star is a massive body of plasma in outer space that is currently producing or has produced energy through nuclear fusion. ... -1... For the software company, see Cygnus Solutions. ... An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... 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 binary star system consists of two stars both orbiting around their barycenter. ...


This system should not be confused with 16 Cygni, which includes a Sun-like star with a very eccentric planet. 16 Cygni is a double star system 85 light years from Earth. ...

Contents


General information

61 Cygni's proper motion is so great, relatively speaking, that its apparent position shifts by an amount equal to the width of the full moon in a mere 150 years. The Galileo spacecraft took this composite image on 7 December 1992 on its way to explore the Jupiter system in 1995-97. ...


This large proper motion, the largest known for any star at the time, made 61 Cygni a candidate for the determination of its distance by the method of parallax when the quality of astronomical observations first made this possible. The star therefore has the distinction of being the first star (excluding the Sun) to have its distance determined. This was accomplished by Friedrich Wilhelm Bessel in 1838 who arrived at a figure close to the currently accepted value of 11.4 light years. Parallax (Greek: παραλλαγή (parallagé) = alteration) is the change of angular position of two stationary points relative to each other as seen by an observer, due to the motion of said observer. ... The Sun is the star at the centre of our Solar system. ... 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). ... 1838 was a common year starting on Monday (see link for calendar). ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ...


Only a few years later, however, Groombridge 1830 was discovered to have a larger proper motion. 61 Cygni retains the distinction of having the largest proper motion of any star visible with the naked eye (although Groombridge 1830 at magnitude 6.4 can be seen with the naked eye under exceptionally dark skies). Groombridge 1830 is a star. ... A naked eye is a figure of speech, referring to human eyes unaided by enhancing equipment such as a telescope or binoculars. ...


Subsequent observations showed that, in addition to the closeness of the star, the high proper motion was attributable to its actual velocity relative to the Sun being large and almost transverse to our line of sight to the star. 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...


From the point of the view of the casual astronomical observer, 61 Cygni is not particularly spectacular.


The binary system

Although it appears to be a single star to the naked eye, 61 Cygni is in fact a widely separated binary system, composed of two K class (orange) main sequence stars, 61 Cygni A and 61 Cygni B. The brighter star 61 Cygni A is of apparent magnitude 5.2, the fainter 61 Cygni B is 6.1. The two orbit their common barycenter in a period of 653.2 years. A binary star system consists of two stars both orbiting around their barycenter. ... 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. ... Hertzsprung-Russell diagram The main sequence of the Hertzsprung-Russell diagram is the curve where the majority of stars are located in this diagram. ... 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. ... The barycenter (from the Greek βαρύκεντρον) is the center of mass of two or more bodies which are orbiting each other, and is the point around which both of them orbit. ...


An observer using 7×50 binoculars can find 61 Cygni two binocular fields south-east of the bright star Deneb. An observer using larger binoculars, or a telescope, will be able to resolve the two components of the binary. Binoculars A binocular (from Latin, bi-, two-, and oculus, eye) is a hand-held tool used to make distant objects appear closer by passing the image through two adjacent series of lenses, and erecting prisms. ... Cygnus, the constellation in which Deneb is located. ... 50 cm refracting telescope at Nice Observatory. ...


61 Cygni B's planet

61 Cygni B has been claimed to have a planet or brown dwarf companion, but the claim has not been confirmed. Brown turds are sub-stellar objects (~5 to 90 Jupiter masses) that do not fuse hydrogen into helium in their cores, as do stars on the main sequence, but have fully convective surfaces and interiors, with no chemical differentiation by depth. ...


61 Cygni in Fiction

  • 61 Cygni (Star Trek) is held by many fans of Star Trek to be the home star system of the Tellarite race.
  • In Blake's 7, the region around 61 Cygni is the only area near Earth that has not been surveyed, since it is home to an alien race which is hostile to mankind, going so far as to release a virus on a Federation base via a piece of space debris.
  • 61 Cygni (Foundation universe) is one of Lord Dorwin's hypothetical originary planets of the human race in Isaac Asimov's Foundation Series.
  • 61 Cygni (or 'Swan') is the sun of the planet Sky's Edge in Alastair Reynolds' Revelation Space universe.
  • 61 Cygni A is the sun around which the planet Mesklin revolves in Hal Clement's series of short stories.
  • In Clifford D. Simak's novel Time and Again, 61 Cygni is a mysterious stellar system whose planets are impossible to approach.

http://www. ... Tellarites are a fictional species from the planet Tellar from the Star Trek television show. ... Blakes 7 was a BBC science fiction television series created by Terry Nation that ran four seasons from January 2, 1978 to December 21, 1981. ... This is a list of minor planets in Isaac Asimovs Foundation, Robot, and Empire series. ... Dr. Isaac Asimov enthroned with symbols of his lifes work (Rowena Morrill) Dr. Isaac Asimov (c. ... Hari Seldons holographic image, pictured on a paperback edition of Foundation, appears at various times in the First Foundations history, to guide it through the social and economic crises that befall it. ... Skys Edge is a fictional planet located in the 61 Cygni system and appears in Alastair Reynolds Revelation Space universe. ... Alastair Reynolds is a Welsh science fiction author. ... Revelation Space cover Revelation Space is a 2000 hard science fiction space opera novel by author Alastair Reynolds. ... Mesklin is the name of a fictional superjovian planet created by Hal Clement and used in a number of his stories. ... Harry Clement Stubbs (May 30, 1922 - October 29, 2003), better known by the pen name Hal Clement, was an American science fiction writer, a leader of the subgenre hard science fiction. ... Clifford Donald Simak ( August 3, 1904 - April 25, 1988) was an American science fiction author. ...

See also

This list of the nearest stars to Earth is ordered by increasing distance out to a maximum of 5 parsecs (16. ...

External links


 
 

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