軫宿二

軫（zhěn）宿（xiù）二（Epsilon Corvi，ε Crv，ε Corvi）是在南天星座烏鴉座的一顆恆星，它的固有名稱Minkar /ˈmɪŋkɑːr/，源自阿拉伯語的 منقار 「minqar」，意思是「烏鴉的喙」。它的視星等為+3.0， 位於距離地球318光年（97秒差距）之處。 在中國，它是軫宿的第二顆星。 軫宿二是一顆紅巨星，其恆星分類為K2III。它已經耗盡了核心的氫，在演化上易經遠離主序列。它的質量約為太陽的3倍。以干涉測量術量測得到這顆恆星的角直徑大約為4.99 毫角秒，以其估計的距離，它的真實半徑大約相當於太陽半徑的52倍。表面的有效溫度是7003432000000000000♠4320 K，使其具有K型恆星特有的橙色色調。它的質量大約是太陽的4倍，在其生命的大部分時間裏都是光譜類型為B5V的主序星。 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, November 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, S2CID 18759600, arXiv:0708.1752 , doi:10.1051/0004-6361:20078357  Celis S., L., Photoelectric photometry of late-type variable stars, Astronomy and Astrophysics Supplement Series, October 1975, 22: 9–17, Bibcode:1975A&AS...22....9C  Houk, Nancy, Michigan catalogue of two-dimensional spectral types for the HD stars 4, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, 1979, Bibcode:1988mcts.book.....H  Wielen, R.; et al, Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions, Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg (Astronomisches Rechen-Institut Heidelberg), 1999, 35 (35): 1, Bibcode:1999VeARI..35....1W  Carney, Bruce W.; et al, Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars, The Astronomical Journal, March 2008, 135 (3): 892–906, Bibcode:2008AJ....135..892C, S2CID 2756572, arXiv:0711.4984 , doi:10.1088/0004-6256/135/3/892  Melo, C. H. F.; et al, On the nature of lithium-rich giant stars. Constraints from beryllium abundances, Astronomy and Astrophysics, August 2005, 439 (1): 227–235, Bibcode:2005A&A...439..227M, S2CID 10580797, arXiv:astro-ph/0504133 , doi:10.1051/0004-6361:20041805  Lang, Kenneth R., Astrophysical formulae, Astronomy and astrophysics library 1 3rd, Birkhäuser, 2006 [2024-04-02], ISBN 3-540-29692-1, （原始内容存档于2023-07-28） . The radius (R*) is given by: 2 ⋅ R ∗ = ( 10 − 3 ⋅ 97 ⋅ 4.99 )   AU 0.0046491   AU / R ⨀ ≈ 104 ⋅ R ⨀ {\displaystyle {\begin{aligned}2\cdot R_{*}&={\frac {(10^{-3}\cdot 97\cdot 4.99)\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{\bigodot }}}\\&\approx 104\cdot R_{\bigodot }\end{aligned}}} McWilliam, Andrew, High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances, Astrophysical Journal Supplement Series, December 1990, 74: 1075–1128, Bibcode:1990ApJS...74.1075M, doi:10.1086/191527   MINKAR -- Variable Star, SIMBAD (Centre de Données astronomiques de Strasbourg), [2012-01-23], （原始内容存档于2024-04-11）  Al-Sufi, Book Of Fixed Stars, Constellation: The Crow. [2024-04-02]. （原始内容存档于2020-10-03）.  （中文） 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. （中文） 香港太空館 - 研究資源 - 亮星中英對照表 互联网档案馆的存檔，存档日期January 30, 2011，., Hong Kong Space Museum. Accessed on line November 23, 2010. Richichi, A.; Percheron, I.; Khristoforova, M., CHARM2: An updated Catalog of High Angular Resolution Measurements, Astronomy and Astrophysics, February 2005, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039   The Colour of Stars, Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004 [2012-01-16], （原始内容存档于2012-03-18）  Kaler, James B. (Jim), Minkar, Stars (University of Illinois), [12 July 2015], （原始内容存档于2021-04-15）