西上將

西上將（σ Leo / 狮子座σ）也称太微右垣二，是狮子座的一颗蓝白恒星，在中国古代星官中属于太微垣的太微右垣。它视星等为+4.05，是狮子座的第四亮星，光谱型B9.5V。

西上將

觀測資料 曆元 J2000
星座	狮子座
星官
赤經	11h 21m 08.1943s[1]
赤緯	+06° 01′ 45.558″[1]
視星等（V）	4.046[2]
特性
光谱分类	B9.5 Vs[3]
U−B 色指数	–0.12[4]
B−V 色指数	–0.06[4]
天体测定
徑向速度 (Rv)	–5.3[5] km/s
自行 (μ)	赤经：–91.76[1] mas/yr 赤纬：–12.83[1] mas/yr
视差 (π)	15.24 ± 0.81[1] mas
距离	210 ± 10 ly (66 ± 3 pc)
绝对星等 (MV)	−0.10[6]
詳細資料
質量	2.76[7] M☉
半徑	3.3[8] R☉
表面重力 (log g)	7000383000000000000♠3.83±0.03[9]
亮度	133[6] L☉
溫度	10,250[8] K
金属量 [Fe/H]	+0.0[8] dex
自轉速度 (v sin i)	70[10] km/s
年齡	293[7] Myr
其他命名
σ Leo、​77 Leo、​BD−06° 2437、​FK5 427、​HD 98664、​HIP 55434、​HR 4386、​SAO 118804[11]
參考資料庫
SIMBAD	资料

参考文献

1. Perryman, M. A. C.; et al. The HIPPARCOS Catalogue. Astronomy & Astrophysics. April 1997, 323: L49–L52. Bibcode:1997A&A...323L..49P.
2. Cousins, A. W. J., Standardisation of broad band photometry of equatorial standards, South Africa Astronomical Observatory Circular, 1984, 8: 59−67, Bibcode:1984SAAOC...8...59C.
3. Chini, R.; et al, spectroscopic survey on the multiplicity of high-mass stars, Monthly Notices of the Royal Astronomical Society, August 2012, 424 (3): 1925−1929, Bibcode:2012MNRAS.424.1925C, arXiv:1205.5238 , doi:10.1111/j.1365-2966.2012.21317.x
4. Johnson, H. L.; Iriarte, B.; Mitchell, R. I.; Wisniewskj, W. Z. UBVRIJKL photometry of the bright stars. Communications of the Lunar and Planetary Laboratory. 1966, 4 (99). Bibcode:1966CoLPL...4...99J.
5. Wilson, Ralph Elmer. General Catalogue of Stellar Radial Velocities. Washington: Carnegie Institution of Washington. 1953. Bibcode:1953GCRV..C......0W.
6. Anderson, E.; Francis, Ch., XHIP: An extended hipparcos compilation, Astronomy Letters, 2012, 38 (5): 331, Bibcode:2012AstL...38..331A, arXiv:1108.4971 , doi:10.1134/S1063773712050015.
7. David, Trevor J.; Hillenbrand, Lynne A., The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets, The Astrophysical Journal, 2015, 804 (2): 146, Bibcode:2015ApJ...804..146D, arXiv:1501.03154 , doi:10.1088/0004-637X/804/2/146.
8. Lipski, Ł.; Stȩpień, K. Effective temperatures of magnetic chemically peculiar stars from full spectral energy distributions. Monthly Notices of the Royal Astronomical Society. March 2008, 385 (1): 481–492. Bibcode:2008MNRAS.385..481L. arXiv:0712.3664 . doi:10.1111/j.1365-2966.2008.12856.x.
9. Fitzpatrick, E. L.; Massa, D., Determining the Physical Properties of the B Stars. II. Calibration of Synthetic Photometry, The Astronomical Journal, March 2005, 129 (3): 1642–1662, Bibcode:2005AJ....129.1642F, arXiv:astro-ph/0412542 , doi:10.1086/427855
10. Bernacca, P. L.; Perinotto, M. A catalogue of stellar rotational velocities. Contributi Osservatorio Astronomico di Padova in Asiago. 1970, 239 (1). Bibcode:1970CoAsi.239....1B.
11. sig Leo -- Star. SIMBAD. Centre de Données astronomiques de Strasbourg. [2010-06-23]. （原始内容存档于2016-03-04）.