| 词条 | Alpha Coronae Australis |
| 释义 |
| name = α Coronae Australis}}{{Starbox image | image = | caption=Location of α CrA (circled) }}{{Starbox observe | epoch = J2000.0 | equinox = J2000.0 (ICRS) | constell = Corona Australis | ra ={{RA|19|09|28.34097}}[1] | dec ={{DEC|–37|54|16.1022}}[1] | appmag_v=4.102[1] }}{{Starbox character | class = A2Va[2] | b-v = +0.04[2] | u-b = +0.06[2] | variable= }}{{Starbox astrometry | radial_v=−18.4[2] | prop_mo_ra=84.87[2] | prop_mo_dec=−95.99[2] | parallax=26.02 | p_error=0.25 | parallax_footnote=[3] | absmag_v=1.11[4] }}{{Starbox detail | mass=2.3[5] | radius=2.3[5] | luminosity=31[5] | temperature=9,100[5] | metal_fe= | rotational_velocity=195[6] | age_myr=254[1] }}{{Starbox catalog | names= Meridiana, α CrA, CD−38° 13350, HR 7254, HD 178253, FK5 718, HIP 94114, SAO 210990, GC 26360, IRAS 19060-3759, 2MASS J19092834-3754157 }}{{Starbox reference | Simbad=HD+178253 }}{{Starbox end}} Alpha Coronae Australis (α Coronae Australis, abbreviated Alf CrA, α CrA), also named Meridiana,[7] is the brightest star in the constellation of Corona Australis and is located about 125 light-years from Earth. Nomenclatureα Coronae Australis (Latinised to Alpha Coronae Australis) is the star's Bayer designation. It is the only star in the constellation with a traditional proper name, Alphekka Meridiana (Latin for 'Alphekka South'), after Alphecca, the brightest star in the constellation Corona Borealis. The name Alphecca or Alphekka is Arabic, short for نير الفكّة nayyir al-fakka "the bright (star) of the broken (ring of stars)".[8] In 2016, the IAU organized a Working Group on Star Names (WGSN)[9] to catalog and standardize proper names for stars. The WGSN approved the name Meridiana for this star on 5 September 2017 and it is now so included in the List of IAU-approved Star Names.[7] In Chinese, {{lang|zh|鱉}} ({{lang|zh-Latn|Biē}}), meaning River Turtle, refers to an asterism consisting of Alpha Coronae Australis, Alpha Telescopii, Eta¹ Coronae Australis, Zeta Coronae Australis, Delta Coronae Australis, Beta Coronae Australis, Gamma Coronae Australis, Epsilon Coronae Australis, HD 175362, Kappa² Coronae Australis and Theta Coronae Australis.[10] Consequently, Alpha Coronae Australis itself is known as {{lang|zh|鱉六}} ({{lang|zh-Latn|Biēliù}}, {{lang-en|the Sixth Star of River Turtle}}.).[11] PropertiesAlpha Coronae Australis belongs to the spectral class A2Va, making it an A-type star like Vega. Like the latter, it has excess infrared radiation, which indicates it may be ringed by a disk of dust.[5] It has an apparent magnitude of +4.10.[2] The star's mass and radius are estimated at 2.3 times the Sun's mass and radius. With an effective temperature of roughly 9,100 K, the star radiates a total luminosity of about 31 times the Sun's.[5] This star is roughly 254 million years old.[1] A rapidly rotating star, it spins at almost 200 km per second at the equator, making a complete revolution in approximately 14 hours,[6] close to its breakup velocity. See also
References1. ^1 2 {{citation | display-authors=1 | last1=Song | first1=Inseok | last2=Caillault | first2=J.-P. | last3=Barrado y Navascués | first3=David | last4=Stauffer | first4=John R. | title=Ages of A-Type Vega-like Stars from uvbyβ Photometry | journal=The Astrophysical Journal | volume=546 | issue=1 | pages=352–357 |date=February 2001 | doi=10.1086/318269 | bibcode=2001ApJ...546..352S |arxiv = astro-ph/0010102 }} {{Stars of Corona Australis}}2. ^1 2 3 4 5 6 {{cite simbad | title =* alf CrA | accessdate=2012-09-02}} 3. ^1 2 {{cite journal | author=van Leeuwen, F. | title=Validation of the new Hipparcos reduction | journal=Astronomy and Astrophysics |date=November 2007 | volume=474 | issue=2 | pages=653–664 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 |arxiv = 0708.1752 }} 4. ^{{cite web |title=α Coronae Australis (star) |publisher=Wolfram Alpha |url=http://www.wolframalpha.com/input/?i=alpha+coronae+australis |accessdate=2012-09-02}} 5. ^1 2 3 4 5 {{cite web | title=ALFECCA MERIDIANA (Alpha Coronae Australis) | publisher=University of Illinois | work=Stars | first1=James B. | last1=Kaler | url=http://stars.astro.illinois.edu/sow/alfecca.html | accessdate=2012-09-02}} 6. ^1 {{cite journal | author=Royer, F. | author2=Zorec, J. | author3=Gómez, A. E. | title=Rotational velocities of A-type stars. III. Velocity distributions |date=February 2007 | journal=Astronomy and Astrophysics | volume=463 | issue=2 | pages=671–682 | doi=10.1051/0004-6361:20065224 | bibcode=2007A&A...463..671R|arxiv = astro-ph/0610785 }} 7. ^1 {{cite web | url=https://www.iau.org/public/themes/naming_stars/ | title=Naming Stars |publisher=IAU.org |accessdate=16 December 2017}} 8. ^{{cite book | author=Allen, Richard Hinckley | date=1963 |origyear=1899 | title=Star Names: Their Lore and Meaning | edition=Reprint | publisher=Dover Publications Inc. | location=New York, NY | url= http://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Corona_Australis*.html | isbn=0-486-21079-0 | pages = 172–73}} 9. ^{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|accessdate=22 May 2016}} 10. ^{{zh icon}} 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}}. 11. ^{{zh icon}} 香港太空館 - 研究資源 - 亮星中英對照表 {{webarchive|url=https://web.archive.org/web/20081025110153/http://www.lcsd.gov.hk/CE/Museum/Space/Research/StarName/c_research_chinengstars_ala_alz.htm |date=2008-10-25 }}, Hong Kong Space Museum. Accessed on line November 23, 2010. 8 : Corona Australis|Bayer objects|Durchmusterung objects|Henry Draper Catalogue objects|Hipparcos objects|HR objects|Stars with proper names|A-type main-sequence stars |
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