[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/cygnus-ob2-8a-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/en\/wiki24\/cygnus-ob2-8a-wikipedia\/","headline":"Cygnus OB2-8A – Wikipedia","name":"Cygnus OB2-8A – Wikipedia","description":"before-content-x4 From Wikipedia, the free encyclopedia after-content-x4 Spectroscopic binary star near the center of Cygnus OB2 Cygnus OB2 #8A after-content-x4","datePublished":"2019-12-11","dateModified":"2019-12-11","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/en\/wiki24\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c9645c498c9701c88b89b8537773dd7c?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"Enzyklop\u00e4die","logo":{"@type":"ImageObject","@id":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","url":"https:\/\/wiki.edu.vn\/wiki4\/wp-content\/uploads\/2023\/08\/download.jpg","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/en.wikipedia.org\/wiki\/Special:CentralAutoLogin\/start?type=1x1","url":"https:\/\/en.wikipedia.org\/wiki\/Special:CentralAutoLogin\/start?type=1x1","height":"1","width":"1"},"url":"https:\/\/wiki.edu.vn\/en\/wiki24\/cygnus-ob2-8a-wikipedia\/","about":["Wiki"],"wordCount":3815,"articleBody":"     (adsbygoogle = window.adsbygoogle || []).push({});before-content-x4From Wikipedia, the free encyclopedia       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4Spectroscopic binary star near the center of Cygnus OB2Cygnus OB2 #8A       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4Observation dataEpoch J2000\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Equinox J2000ConstellationCygnusRight ascension20h 33m 15.07905s[1]Declination+41\u00b0\u00a018\u2032\u00a050.4762\u2033[1]Apparent\u00a0magnitude\u00a0(V)9.06[2]CharacteristicsSpectral\u00a0typeO6If + O5.5III(f)[3]U\u2212B color index+0.15[4]B\u2212V color index+1.29[4]AstrometryRadial velocity (Rv)125.56[5]\u00a0km\/sProper motion (\u03bc) RA:\u00a0\u22122.664[5]\u00a0mas\/yr Dec.:\u00a0\u22124.895[5]\u00a0mas\/yr Parallax (\u03c0)0.6058\u00a0\u00b1\u00a00.0191\u00a0mas[5]Distance5,400 \u00b1 200\u00a0ly (1,650 \u00b1 50\u00a0pc)Absolute\u00a0magnitude\u00a0(MV)\u22126.78[6]Orbit[7]Period (P)21.9 daysSemi-major axis (a)71\u00a0R\u2609[8]Eccentricity (e)0.24Semi-amplitude (K1)(primary)82.8 km\/sSemi-amplitude (K2)(secondary)95.8 km\/sDetails[8]Cyg OB2 #8A1Mass44.1\u00a0M\u2609Radius20\u00a0R\u2609Luminosity650,000\u00a0L\u2609Surface gravity (log\u00a0g)3.48\u00a0cgsTemperature36,800\u00a0KCyg OB2 #8A2Mass37.4\u00a0M\u2609Radius14.8\u00a0R\u2609Luminosity468,000\u00a0L\u2609Surface gravity (log\u00a0g)3.67\u00a0cgsTemperature39,200\u00a0KAge2[6]\u00a0MyrOther designations Schulte\u00a08A, 1E\u00a0203127+4108.5, TYC\u00a03161-1325-1, ADS\u00a014000\u00a0A, 2E\u00a04382, HIP\u00a0101425, UBV\u00a017839, AG+41\u00b0\u00a01925, 2E\u00a02031.4+4108, IDS\u00a020297+4058, LS\u00a0III\u00a0+41\u00a037, Cyg OB2-8A, 1ES\u00a02031+41.1, 2MASS\u00a0J20331508+4118504, BD+40 4227, GCRV\u00a020036, PPM\u00a060129, CCDM\u00a0J20332+4119A, 1RXS\u00a0J203315.8+411848, CGO\u00a0605, GOS\u00a0G080.22+00.79 01, SAO\u00a049781, CSI+40\u00a04227\u00a01, GSC\u00a003161-01325,Gaia DR2 2067784624247057920 Database referencesSIMBADdataCygnus OB2 #8A is a double-lined spectroscopic binary located near the centre of the Cygnus OB2 association located 5,500 light years away.Discovery[edit]Until 1951 Cyg OB2 #8 had been known only as an anonymous catalogue entry in the Bonner Durchmusterung.  Then it was identified as one of several highly luminous hot stars close together in Cygnus.  Despite being commonly referred to as Schulte #8A, the number 8 was first published in an earlier paper.[9]  Schulte identified the grouping as a massive stellar association and split star #8 into four components, including #8A.[10]The Cygnus OB2 #8A system contains two massive luminous O class stars in a 21.9 day orbit.  The primary is a 44\u00a0M\u2609supergiant and the secondary is a 37\u00a0M\u2609giant star.[7]  The two stars are not thought to be exchanging mass and their luminosity classes match the main sequence turnoff in the Cyg OB2 association at around O6.[6]  The nearby stars Cyg OB2 #8B, #8C, and #8D, originally thought to be a single star, are all massive and luminous class O stars.       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4References[edit]^ a b Van Leeuwen, F. (2007). “Validation of the new Hipparcos reduction”. Astronomy and Astrophysics. 474 (2): 653\u2013664. arXiv:0708.1752. Bibcode:2007A&A…474..653V. doi:10.1051\/0004-6361:20078357. S2CID\u00a018759600.^ Caballero-Nieves, S. M.; Nelan, E. P.; Gies, D. R.; Wallace, D. J.; Degioia-Eastwood, K.; Herrero, A.; Jao, W.-C.; Mason, B. D.; Massey, P.; Moffat, A. F. J.; Walborn, N. R. (2014). “A High Angular Resolution Survey of Massive Stars in Cygnus OB2: Results from the Hubble Space Telescope Fine Guidance Sensors”. The Astronomical Journal. 147 (2): 40. arXiv:1311.5087. Bibcode:2014AJ….147…40C. doi:10.1088\/0004-6256\/147\/2\/40. S2CID\u00a022036552.^ Cazorla, Constantin; Naz\u00e9, Ya\u00ebl; Rauw, Gregor (2014). “Wind collisions in three massive stars of Cygnus OB2”. Astronomy & Astrophysics. 561: A92. arXiv:1312.1871. Bibcode:2014A&A…561A..92C. doi:10.1051\/0004-6361\/201322539. S2CID\u00a053682076.^ a b Ducati, J. R. (2002). “VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson’s 11-color system”. CDS\/ADC Collection of Electronic Catalogues. 2237. Bibcode:2002yCat.2237….0D.^ a b c d Brown, A. G. A.;  et\u00a0al. (Gaia collaboration) (2021). “Gaia Early Data Release 3: Summary of the contents and survey properties”. Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A…649A…1G. doi:10.1051\/0004-6361\/202039657. S2CID\u00a0227254300. (Erratum:\u00a0doi:10.1051\/0004-6361\/202039657e).  Gaia EDR3 record for this source at VizieR.^ a b c Negueruela, I.; Marco, A.; Herrero, A.; Clark, J. S. (2008). “New very massive stars in Cygnus OB2”. Astronomy and Astrophysics. 487 (2): 575. arXiv:0806.2879. Bibcode:2008A&A…487..575N. doi:10.1051\/0004-6361:200810094. S2CID\u00a010915879.^ a b De Becker, M.; Rauw, G.; Manfroid, J. (2004). “A Spectroscopic study of the non-thermal radio emitter Cyg OB2 #8A: Discovery of a new binary system”. Astronomy and Astrophysics. 424 (3): L39. arXiv:astro-ph\/0408027. Bibcode:2004A&A…424L..39D. doi:10.1051\/0004-6361:200400049. S2CID\u00a016213357.^ a b De Becker, M.; Rauw, G.; Sana, H.; Pollock, A. M. T.; Pittard, J. M.; Blomme, R.; Stevens, I. R.; Van Loo, S. (2006). “XMM-Newton observations of the massive colliding wind binary and non-thermal radio emitter CygOB2#8A [O6If + O5.5III(f)]” (PDF). Monthly Notices of the Royal Astronomical Society. 371 (3): 1280. Bibcode:2006MNRAS.371.1280D. doi:10.1111\/j.1365-2966.2006.10746.x.^ M\u00fcnch, Luis; Morgan, W. W. (1953). “Notes: A Probable Clustering of Blue Giants in Cygnus”. Astrophysical Journal. 118: 161. Bibcode:1953ApJ…118..161M. doi:10.1086\/145737.^ Schulte, D. H. (1956). “New Members of the Association VI Cygni”. Astrophysical Journal. 124: 530. Bibcode:1956ApJ…124..530S. doi:10.1086\/146256.External links[edit]       (adsbygoogle = window.adsbygoogle || []).push({});after-content-x4"},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/en\/wiki24\/cygnus-ob2-8a-wikipedia\/#breadcrumbitem","name":"Cygnus OB2-8A – Wikipedia"}}]}]