[{"@context":"http:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/55-cygni-wikipedia\/#BlogPosting","mainEntityOfPage":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/55-cygni-wikipedia\/","headline":"55 Cygni – Wikipedia","name":"55 Cygni – Wikipedia","description":"From Wikipedia, the free encyclopedia Star in the constellation Cygnus 55 cygni Location of 55 Cyg (circled) Observation data Epoch","datePublished":"2021-11-28","dateModified":"2021-11-28","author":{"@type":"Person","@id":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/author\/lordneo\/#Person","name":"lordneo","url":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/author\/lordneo\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/44a4cee54c4c053e967fe3e7d054edd4?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/44a4cee54c4c053e967fe3e7d054edd4?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:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/0\/02\/Cygnus_constellation_map.svg\/320px-Cygnus_constellation_map.svg.png","url":"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/thumb\/0\/02\/Cygnus_constellation_map.svg\/320px-Cygnus_constellation_map.svg.png","height":"266","width":"320"},"url":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/55-cygni-wikipedia\/","wordCount":4590,"articleBody":"From Wikipedia, the free encyclopedia Star in the constellation Cygnus 55 cygni Location of 55 Cyg (circled) Observation data Epoch J2000\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Equinox J2000 Constellation Cygnus Right ascension  20 h 48 m 56.29119 s [first] Declination +46 \u00b0 06 \u2032 50.8824 \u2033 [first] Apparent\u00a0magnitude\u00a0(V)  4.86 [2] (4.81 – 4.87 [3] )  Characteristics Spectral\u00a0type B2.5ia [4] – B4ia [5] U\u2212B color index \u22120.45 [2] B\u2212V color index +0.42 [2] Variable\u00a0type L [3] or a cyg [6] Astrometry Radial velocity (R in ) \u22127.2 [7] km\/s Proper Motion (M)  GO OUT: \u22122.65 [first] mas\/yr Dec.: \u22122.84 [first] mas\/yr Parallax (P) 1.40 \u00b1 0.17 but [first] Distance 830 [8] \u00a0pc Absolute\u00a0magnitude\u00a0(M IN ) \u22126.93 [8] – \u22127.26 [9] Details [6] Mass 23 [9]  M \u2609 Radius 54 – 65 R \u2609 Luminosity 324,000 – 478,000  L \u2609 Surface gravity (log\u00a0 g ) 2.35 – 2.50\u00a0cgs Temperature 18,600 – 19,000\u00a0K Rotational velocity ( in \u00a0sin\u00a0 i ) sixty one [9] km\/s Other designations Database references Simbad data 55 cygni ( 55 cyg ) is a blue supergiant star in the constellation Cygnus.  It is thought to be a member of the Cygnus OB7 stellar association at about 2,700 light years.  Its apparent magnitude is 4.86, but this is slightly variable and the star is also called V1661 Cyg.  When first analysed, it was classified as an irregular supergiant variable, [11] but subsequent studies have treated it as an Alpha Cygni variable.  It shows pulsations with multiple periods from a few hours to 22 days, and both p- and g-modes. [6] Apart from p- and g-modes, strange mode and associated instabilities have also been found in models of this star. [twelfth] The spectrum also shows variation, leading to different classifications being given for the star. [13] The exact properties of 55 Cygni are not known precisely and are also variable.  It is a hot luminous supergiant several hundred thousand times as luminous as the sun.  This star was originally a standard for the B3 Ia spectral type. [14] The type of pulsations that 55 Cyg exhibits suggest that it was previously a red supergiant that has shed its outer layers.  The most massive red supergiants are expected to pass through a blue supergiant phase before becoming a Wolf-Rayet star and eventually exploding as a type Ib or Ic supernova. [6] References [ edit ] ^ a  b  c  d  It is  Van Leeuven, F. (2007). “Validation of the New Hipparos reduction”. Astronomy and Astrophysics . 474 (2): 653\u2013664. arXiv: 0708.1752 . Bibcode: 2007a & a … 474..653v . doi: 10.1051\/0004-6361: 20078357 . S2CID\u00a0 18759600 .  ^ a  b  c  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  Samus, N. N.; Durlevich, O. V.;  et\u00a0al. (2009). “VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)”. VizieR On-line Data Catalog: B\/GCVS. Originally Published in: 2009yCat….102025S . first . Bibcode: 2009yCat….102025S .  ^  Prinja, R. K.; Massa, D. L. (2010). “Signature of wide-spread clumping in B supergiant winds”. Astronomy and Astrophysics . 521 : L55. arXiv: 1007.2744 . Bibcode: 2010A&A…521L..55P . doi: 10.1051\/0004-6361\/201015252 . S2CID\u00a0 59151633 .  ^  Zorec, J.; Cidale, L.; Arias, M. L.; Fr\u00e9mat, Y.; Murtore, M. F.; Torres, A. F.; MARTAYAN, C. (2009). “Fendal Parameters of B Supergiants From the BCD System. I. Calibration of the (\u03bb_1, d) parameters into teff” Astronomy and Astrophysics . 501 (1): 297\u2013320. arXiv: 0903.5134 . Bibcode: 2009a & a … 501..297z . doi: 10.1051\/0004-6361\/200811147 . S2CID\u00a0 14969137 .  ^ a  b  c  d  Kraus, m.; HAUCKE, M.; Cidale, L. S.; Vetero, R. O. J.; Nickeler, D. H.; N\u00e9meth, P.; Niemczura, e.; Tomi\u0107, S.; Aret, a.; Kub\u00e1t, J.; Kub\u00e1tov\u00e1, B.; Oksala, M. E.; Cur\u00e9, m.; Kami\u0144ski, K.; Dimitrov, w.; Fagas, m.; Poli\u0144ska, M. (2015). “Interplay Between Pulsations and Mass Loss in the Blue Supergiant 55 Cygnus = HD 198478”. Astronomy & Astrophysics . 581 : A75. Arxiv: 1507.01846 . Bibcode: 2015A&A…581A..75K . doi: 10.1051\/0004-6361\/201425383 . S2CID\u00a0 55392478 .  ^  Wilson, Ralph Elmer (1953). “General catalogue of stellar radial velocities”. Washington . Bibcode: 1953GCRV..C……0W .  ^ a  b  Markova, N.; Puls, J. (2008). “Bright OB stars in the Galaxy. IV. Stellar and wind parameters of early to late B supergiants”. Astronomy and Astrophysics . 478 (3): 823. arXiv: 0711.1110 . Bibcode: 2008A&A…478..823M . doi: 10.1051\/0004-6361: 20077919 . S2CID\u00a0 14510634 .  ^ a  b  c  Searle, S. C.; Prinja, R. K.; Massa, D.; Ryans, R. (2008). “Quantitative studies of the optical and UV spectra of Galactic early B supergiants. I. Fundamental parameters”. Astronomy and Astrophysics . 481 (3): 777. arXiv: 02001.4289 . Bibcode: 2008a & a … 481..777s . doi: 10.1051\/0004-6361: 20077125 . S2CID\u00a0 1552752 .  ^  “\/ftp\/cats\/more\/HIP\/cdroms\/cats” . Strasbourg astronomical data center . Strasbourg astronomical Data Center . Retrieved 27 November 2022 .  ^  Fet the Devis, y. Marchonko, Sull, Su. Moxer, I. J. J. I Stery, I. (2009). “A systematic study of variability among OB-stars based on HIPPARCOS photometry” . Astronomy and Astrophysics . 507 (2): 1141. Bibcode: 2009A&A…507.1141L . doi: 10.1051\/0004-6361\/200912304 .  ^  Yadav, Ababay Pratap; Glatzel, Wolfgang (2016). “Stability analysis, non-linear pulsations and mass loss of models for 55 Cygni (HD 198478)” . Monthly Notices of the Royal Astronomical Society . 457 (4): 4330\u20134339. Bibcode: 2016MNRAS.457.4330Y . doi: 10.1093\/mnras\/stw236 . ISSN\u00a0 0035-8711 .  ^  Maharramov, Y. M. (2013). “Spectral variability of the STAR 55 Cyg B3 Ia”. Astronomy Reports . 57 (4): 303\u2013309. Bibcode: 2013EP … 57..303m . doi: 10.1134\/s1063772913030037 . S2CID\u00a0 121606849 .  ^  Morgan, W. W.; Roman, Nancy G. (1950). “Revised Standards for Supergiants on the System of the Yerkes Spectral Atlas”. Astrophysical Journal . 112 : 362. Bibcode: 1950ApJ…112..362M . doi: 10.1086\/145351 .       "},{"@context":"http:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/#breadcrumbitem","name":"Enzyklop\u00e4die"}},{"@type":"ListItem","position":2,"item":{"@id":"https:\/\/wiki.edu.vn\/all2en\/wiki42\/55-cygni-wikipedia\/#breadcrumbitem","name":"55 Cygni – Wikipedia"}}]}]