Skip to main content

Eta Centauri








Eta Centauri


From Wikipedia, the free encyclopedia

Jump to navigation
Jump to search








































































































Eta Centauri





Centaurus constellation map.svg

Red circle.svg






Location of η Centauri (circled)
Observation data
Epoch J2000.0      Equinox J2000.0

Constellation
Centaurus

Right ascension
 14h 35m 30.42416s[1]

Declination
 −42° 09′ 28.1708″[1]

Apparent magnitude (V)
 +2.35[2](2.30 - 2.41[3])
Characteristics

Spectral type
 B1.5 Vne[4]
U−B color index
 −0.862[2]
B−V color index
 −0.215[2]

Variable type
γ Cassiopeiae[3]
Astrometry
Radial velocity (Rv) –0.2[5] km/s
Proper motion (μ) RA: −34.73[1] mas/yr
Dec.: −32.72[1] mas/yr
Parallax (π) 10.67 ± 0.21[1] mas
Distance 306 ± 6 ly
(94 ± 2 pc)
Absolute magnitude (MV) −2.53[6]
Details
Mass
12.0 ± 0.3[7] M☉
Radius 5-6 [8] R☉
Luminosity 8,700[4] L☉
Surface gravity (log g) 3.20[9] cgs
Temperature 25,700[4] K
Rotational velocity (v sin i) 330[4] km/s
Age
5.6 ± 1.0[7] Myr
Other designations
η Cen, CD−41°8917, CPD−41°6839, FK5 537, HD 127972, HIP 71352, HR 5440, SAO 225044.[10]
Database references
SIMBAD data

Eta Centauri, Latinized from η Centauri, is a star in the southern constellation of Centaurus. It has an apparent visual magnitude of +2.35[2] and is located at a distance of around 306 light-years (94 parsecs).[1] In traditional Chinese astronomy, Eta Centauri was known as 庫樓二[11] (meaning: the Second (Star) of Koo Low).[12]


The stellar classification of this star is B1.5 Vne,[4] indicating that it is a B-type main sequence star. The 'n' suffix means that the absorption lines are broadened from rapid rotation. It has a projected rotational velocity of 330 km s−1[4] and completes a full rotation in less than a day. This is a Be star as shown by the 'e' suffix,[13] which means it has variable emissions in its hydrogen spectral lines. This emission can be modeled by a decretion disk of gas that has been ejected from the star and now follows a near Keplerian orbit around the central body.[14] Finally it is slightly variable, and classified as a Gamma Cassiopeiae variable star with multiple periods of variability.[3] The International Variable Star Index lists Eta Centauri as both a Gamma Cassiopeiae variable and a Lambda Eridani variable.[15]


Eta Centauri has about 12[7] times the mass of the Sun, placing it above the dividing line between stars that evolve into white dwarfs and those that turn into supernovae. It is radiating 8,700[4] times as much luminosity as the Sun from its outer atmosphere at an effective temperature of 25,700 K.[4] This heat causes the star to glow with the blue-white hue common to B-type stars.[16] Eta Centauri is a proper motion member of the Upper-Centaurus Lupus sub-group in the Scorpius-Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[9]



See also[edit]


  • Centaurus (Chinese astronomy)


References[edit]





  1. ^ abcdef van Leeuwen, F. (November 2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics. 474 (2): 653–664. arXiv:0708.1752. Bibcode:2007A&A...474..653V. doi:10.1051/0004-6361:20078357..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""""'""'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}


  2. ^ abcd Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement Series, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168


  3. ^ abc Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007–2013)". VizieR On-line Data Catalog: B/gcvs. 1: 02025. Bibcode:2009yCat....102025S.


  4. ^ abcdefgh Balona, L. A.; Dziembowski, W. A. (October 1999), "Excitation and visibility of high-degree modes in stars", Monthly Notices of the Royal Astronomical Society, 309 (1): 221–232, Bibcode:1999MNRAS.309..221B, doi:10.1046/j.1365-8711.1999.02821.x


  5. ^ Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veröff. Astron. Rechen-Inst. Heidelb, Astronomisches Rechen-Institut Heidelberg, 35 (35), Bibcode:1999VeARI..35....1W


  6. ^ Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.


  7. ^ abc Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x


  8. ^ Kaler, James B. "ETA CEN (Eta Centauri)". University of Illinois. Retrieved 2018-09-16.


  9. ^ ab de Geus, E. J.; de Zeeuw, P. T.; Lub, J. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics, 216 (1–2): 44–61, Bibcode:1989A&A...216...44D


  10. ^ "eta Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-03-03.


  11. ^ (in Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005,
    ISBN 978-986-7332-25-7.


  12. ^ Allen, R. H. (1963), Star Names: Their Lore and Meaning (Reprint ed.), New York, NY: Dover Publications Inc., p. 154, ISBN 0-486-21079-0


  13. ^ Janot-Pacheco, E., Leister NV, et al. (1999), "Multi-periodicity of the Be star η Centauri from spectroscopic and photometric observations", Astronomy and Astrophysics Supplement Series, 137 (3): 407, Bibcode:1999A&AS..137..407J, doi:10.1051/aas:1999256


  14. ^ Silaj, J.; Jones, C. E.; Tycner, C.; Sigut, T. A. A.; Smith, A. D. (March 2010), "A Systematic Study of Hα Profiles of Be Stars", Astrophysical Journal Supplement Series, 187 (1): 228–250, Bibcode:2010ApJS..187..228S, doi:10.1088/0067-0049/187/1/228


  15. ^ Watson, C. L. (2006). "The International Variable Star Index (VSX)". The Society for Astronomical Sciences 25th Annual Symposium on Telescope Science. Held May 23–25. 25: 47. Bibcode:2006SASS...25...47W.


  16. ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-10, retrieved 2012-01-16




External links[edit]



  • Eta Centauri by Jim Kaler.










Retrieved from "https://en.wikipedia.org/w/index.php?title=Eta_Centauri&oldid=866307888"





Navigation menu

























(window.RLQ=window.RLQ||).push(function(){mw.config.set({"wgPageParseReport":{"limitreport":{"cputime":"0.620","walltime":"0.765","ppvisitednodes":{"value":2474,"limit":1000000},"ppgeneratednodes":{"value":0,"limit":1500000},"postexpandincludesize":{"value":99230,"limit":2097152},"templateargumentsize":{"value":6006,"limit":2097152},"expansiondepth":{"value":14,"limit":40},"expensivefunctioncount":{"value":3,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":48933,"limit":5000000},"entityaccesscount":{"value":3,"limit":400},"timingprofile":["100.00% 636.082 1 -total"," 43.51% 276.777 1 Template:Reflist"," 23.18% 147.437 1 Template:Lang"," 16.16% 102.792 3 Template:Cite_journal"," 11.12% 70.757 1 Template:Starbox_image"," 10.01% 63.701 10 Template:Citation"," 9.97% 63.421 1 Template:Location_mark"," 9.39% 59.754 1 Template:Location_mark+"," 7.36% 46.846 11 Template:Ifempty"," 5.69% 36.212 5 Template:Navbox"]},"scribunto":{"limitreport-timeusage":{"value":"0.330","limit":"10.000"},"limitreport-memusage":{"value":16019855,"limit":52428800}},"cachereport":{"origin":"mw1266","timestamp":"20181029154313","ttl":1900800,"transientcontent":false}}});mw.config.set({"wgBackendResponseTime":89,"wgHostname":"mw1271"});});
-

Popular posts from this blog

Full-time equivalent

Image
Full-time equivalent From Wikipedia, the free encyclopedia Jump to navigation Jump to search Full-time equivalent ( FTE ) or whole time equivalent ( WTE ) is a unit that indicates the workload of an employed person (or student) in a way that makes workloads or class loads comparable [1] across various contexts. FTE is often used to measure a worker's or student's involvement in a project, or to track cost reductions in an organization. An FTE of 1.0 is equivalent to a full-time worker or student, while an FTE of 0.5 signals half of a full work or school load. [2] Contents 1 U.S. Federal Government 2 In education 2.1 Example 3 Notes 4 References U.S. Federal Government [ edit ] In the U.S. Federal Government, FTE is defined by the Government Accountability Office (GAO) as the number of total hours worked divided by the maximum number of compensable hours in a full-time schedule as
Read more

Bicuculline

Image
Bicuculline From Wikipedia, the free encyclopedia Jump to navigation Jump to search Bicuculline Clinical data ATC code none Identifiers IUPAC name (6 R )-​6-​[(5 S )-​6-​methyl-​5,​6,​7,​8-​tetrahydro​[1,3]dioxolo​[4,5- g ]​isoquinolin-​5-​yl]​furo[3,4- e ]​[1,3]​benzodioxol-​8(6 H )-​one CAS Number 485-49-4   Y PubChem CID 10237 IUPHAR/BPS 2312 ChemSpider 9820   Y UNII Y37615DVKC ChEBI CHEBI:3092   N ChEMBL ChEMBL417990   N ECHA InfoCard 100.006.927 Chemical and physical data Formula C 20 H 17 N O 6 Molar mass 367.352 g/mol 3D model (JSmol) Interactive image Melting point 215 °C (419 °F) SMILES O=C1O[C@H](c3c1c2OCOc2cc3)[C@@H]5c4cc6OCOc6cc4CCN5C InChI InChI=1S/C20H17NO6/c1-21-5-4-10-6-14-15(25-8-24-14)7-12(10)17(21)18-11-2-3-13-19(26-9-23-13)16(11)20(22)27-18/h2-3,6-7,17-18H,4-5,8-9H2,1H3/t17-,18+/m0/s1   Y Key:IYGYMKDQCDOMRE-ZWKOTPCHSA-N
Read more

さくらももこ

Image
さくら ももこ 本名 非公開 [1] 生誕 ( 1965-05-08 ) 1965年5月8日 日本・静岡県清水市 （現・静岡市清水区） 死没 ( 2018-08-15 ) 2018年8月15日（53歳没） 日本・東京都目黒区 国籍 日本 職業 漫画家 エッセイスト 作詞家 活動期間 1984年 - 2018年 ジャンル 少女漫画 青年漫画 児童漫画 代表作 『ちびまる子ちゃん』 『コジコジ』 受賞 1989年：第13回講談社漫画賞少女部門 （『ちびまる子ちゃん』） 1990年：第32回日本レコード大賞 （『おどるポンポコリン』作詞） 公式サイト さくらプロダクション テンプレートを表示 さくら ももこ （1965年5月8日 - 2018年8月15日 [2] ）は、日本の漫画家、エッセイスト、作詞家、脚本家。また、自身の少女時代をモデルとした代表作のコミック『ちびまる子ちゃん』の主人公の名前でもある。静岡県清水市（現・静岡市清水区）出身。血液型はA型。身長159cm。一男の母親。 代表作のコミック『ちびまる子ちゃん』の単行本の売上は累計3000万部を超える。また、エッセイストとしても独特の視点と語り口で人気が高く、初期エッセイ集三部作『もものかんづめ』『さるのこしかけ』『たいのおかしら』はいずれもミリオンセラーを記録。 目次 1 経歴 2 人物・交遊関係 3 主な作品 3.1 漫画 3.2 エッセイ 3.3 作詞 3.4 詩集 3.5 雑誌・ムック本 3.6 翻訳 3.7 絵本、ドラマ脚本他 3.8 ラジオ出演 3.9 その他 4 関係人物 4.1 アシスタント 4.2 さくらももこを演じた人物 5 脚注 5.1 注釈 5.2 出典 6 外部リンク 経歴 年譜形式の経歴は推奨されていません 。人物の伝記は流れのあるまとまった文章で記述し、年譜は補助的な使用にとどめてください。 （ 2018年8月 ） 清水市立（当時）入江小学校
Read more