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- Beta_Lyrae abstract "Beta Lyrae (β Lyr, β Lyrae) is a binary star system approximately 960 light-years (290 parsecs) away in the constellation Lyra. Beta Lyrae has the traditional name Sheliak (occasionally Shelyak), from الشلياق šiliyāq, the Arabic name of the constellation Lyra. The Bayer designation for this star was given by the German astronomer Johann Bayer with the publication of his star atlas Uranometria in 1603. It was given the Flamsteed designation 10 Lyrae by John Flamsteed in 1712 with the first publication of his star catalogue. The variable luminosity of this system was discovered in 1784 by the British amateur astronomer John Goodricke.Beta Lyrae is a semidetached binary system made up of a stellar class B7II primary star and a secondary that is probably also a B-type star. The fainter, less massive star (B7II) in the system was once the more massive member of the pair, which caused it to evolve away from the main sequence first and become a giant star. Because the pair are in a close orbit, as this star expanded into a giant it filled its Roche lobe and transferred most of its mass over to its companion. The secondary, now more massive star is surrounded by an accretion disk from this mass transfer, with bipolar, jet-like features projecting perpendicular to the disk. This accretion disk blocks our view of the secondary star, lowering its apparent luminosity and making it difficult for astronomers to pinpoint what its stellar type is. The amount of mass being transferred between the two stars is about 2 × 10–5 solar masses per year, or the equivalent of the Sun's mass every 50,000 years, which results in an increase in orbital period of about 19 seconds each year.The orbital plane of this system is nearly aligned with the line of sight from the Earth, so the two stars periodically eclipse each other. This causes Beta Lyrae to regularly change its apparent magnitude from +3.4 to +4.6 over an orbital period of 12.9414 days. The two components are so close together that they cannot be resolved with optical telescopes, forming a spectroscopic binary. In 2008, the primary star and the accretion disk of the secondary star were resolved and imaged using the CHARA Array interferometer and the Michigan InfraRed Combiner (MIRC) in the near infrared H band (see video below), allowing the orbital elements to be computed for the first time.Two other stars appear close to the line of sight of Beta Lyrae, but are not part of the binary system. One, at an angular distance of 45.7", is of spectral type B7V, has an apparent magnitude of +7.2, and can easily be seen with binoculars. It is about 80 times as luminous as the Sun and is also a spectroscopic binary with a period of 4.34 days. The other is magnitude 9.9v separation 86" and with a luminosity 7 times that of the Sun.".
- Beta_Lyrae thumbnail Lyra_IAU.svg?width=300.
- Beta_Lyrae wikiPageExternalLink books?id=aJavy9Yk1yoC&pg=PA29.
- Beta_Lyrae wikiPageExternalLink sheliak.html.
- Beta_Lyrae wikiPageExternalLink vsots_betalyr.
- Beta_Lyrae wikiPageExternalLink page3.html.
- Beta_Lyrae wikiPageExternalLink betalyra.
- Beta_Lyrae wikiPageID "1988337".
- Beta_Lyrae wikiPageRevisionID "605292929".
- Beta_Lyrae absmagV "−3.91".
- Beta_Lyrae appmagV "3.52".
- Beta_Lyrae bV "+0.00".
- Beta_Lyrae class "B6–8II / B".
- Beta_Lyrae component "β Lyr A".
- Beta_Lyrae component "β Lyr B".
- Beta_Lyrae constell Lyra.
- Beta_Lyrae eccentricity "0".
- Beta_Lyrae epoch Epoch_(astronomy).
- Beta_Lyrae hasPhotoCollection Beta_Lyrae.
- Beta_Lyrae luminosity "26300".
- Beta_Lyrae luminosity "6500".
- Beta_Lyrae name "Beta Lyrae B".
- Beta_Lyrae pError "0.17".
- Beta_Lyrae parallax "3.39".
- Beta_Lyrae periodUnitless "1118136.96".
- Beta_Lyrae propMoDec "−3.53".
- Beta_Lyrae propMoRa "1.9".
- Beta_Lyrae radialV "−19.2".
- Beta_Lyrae temperature "13300".
- Beta_Lyrae uB "−0.56".
- Beta_Lyrae variable Beta_Lyrae_variable.
- Beta_Lyrae subject Category:B-type_main-sequence_stars.
- Beta_Lyrae subject Category:Bayer_objects.
- Beta_Lyrae subject Category:Beta_Lyrae_variables.
- Beta_Lyrae subject Category:Binary_stars.
- Beta_Lyrae subject Category:Lyra_(constellation).
- Beta_Lyrae subject Category:Objects_within_1000_ly_of_Earth.
- Beta_Lyrae subject Category:Spectroscopic_binaries.
- Beta_Lyrae subject Category:Stars_with_proper_names.
- Beta_Lyrae type B-typeMainSequenceStars.
- Beta_Lyrae type BayerObjects.
- Beta_Lyrae type BetaLyraeVariables.
- Beta_Lyrae type BinaryStar109221070.
- Beta_Lyrae type BinaryStars.
- Beta_Lyrae type CelestialBody109239740.
- Beta_Lyrae type NaturalObject100019128.
- Beta_Lyrae type Object100002684.
- Beta_Lyrae type PhysicalEntity100001930.
- Beta_Lyrae type SpectroscopicBinaries.
- Beta_Lyrae type Star109444100.
- Beta_Lyrae type StarsWithProperNames.
- Beta_Lyrae type Thing100002452.
- Beta_Lyrae type Variable109468959.
- Beta_Lyrae type Whole100003553.
- Beta_Lyrae type CelestialBody.
- Beta_Lyrae type Star.
- Beta_Lyrae type PhysicalBody.
- Beta_Lyrae comment "Beta Lyrae (β Lyr, β Lyrae) is a binary star system approximately 960 light-years (290 parsecs) away in the constellation Lyra. Beta Lyrae has the traditional name Sheliak (occasionally Shelyak), from الشلياق šiliyāq, the Arabic name of the constellation Lyra. The Bayer designation for this star was given by the German astronomer Johann Bayer with the publication of his star atlas Uranometria in 1603.".
- Beta_Lyrae label "Beta Lyrae".
- Beta_Lyrae label "Beta Lyrae".
- Beta_Lyrae label "Beta Lyrae".
- Beta_Lyrae label "Beta Lyrae".
- Beta_Lyrae label "Beta Lyrae".
- Beta_Lyrae label "Beta Lyrae".
- Beta_Lyrae label "Sheliak".
- Beta_Lyrae label "Sheliak".
- Beta_Lyrae label "Шелиак".
- Beta_Lyrae label "الشلياق".
- Beta_Lyrae label "こと座ベータ星".
- Beta_Lyrae label "渐台二".
- Beta_Lyrae sameAs Sheliak.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae sameAs こと座ベータ星.
- Beta_Lyrae sameAs 거문고자리_베타.
- Beta_Lyrae sameAs Sheliak.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae sameAs m.06c5yx.
- Beta_Lyrae sameAs Q13352.
- Beta_Lyrae sameAs Q13352.
- Beta_Lyrae sameAs Beta_Lyrae.
- Beta_Lyrae wasDerivedFrom Beta_Lyrae?oldid=605292929.
- Beta_Lyrae depiction Lyra_IAU.svg.
- Beta_Lyrae isPrimaryTopicOf Beta_Lyrae.
- Beta_Lyrae name "Beta Lyrae".