軒轅四
觀測資料 曆元 J2000 | |
---|---|
星座 | 天貓座 |
星官 | 軒轅 (星宿) |
赤經 | 09h 21m 03.30074s[1] |
赤緯 | +34° 23′ 33.2245″[1] |
視星等(V) | +3.14[2] |
特性 | |
光谱分类 | K7 III[3] |
U−B 色指数 | +1.95[4] |
B−V 色指数 | +1.55[4] |
天体测定 | |
徑向速度 (Rv) | 37.15[5] km/s |
自行 (μ) | 赤经:–223.63[1] mas/yr 赤纬:15.18[1] mas/yr |
视差 (π) | 16.06 ± 0.17[1] mas |
距离 | 203 ± 2 ly (62.3 ± 0.7 pc) |
詳細資料 | |
質量 | ~2[6] M☉ |
半徑 | 54.50 ± 3.02[7] R☉ |
表面重力 (log g) | 1.5[5] |
亮度 | 673 ± 83[7] L☉ |
溫度 | 3,882[5] K |
金属量 [Fe/H] | –0.26[5] dex |
自轉速度 (v sin i) | 6.4[5] km/s |
年齡 | 1.4[6] Gyr |
其他命名 | |
參考資料庫 | |
SIMBAD | 资料 |
軒轅四(α Lyn,α Lyncis)是在北天星座天貓座的一顆視星等+3.13的亮星[4]。不尋常的是,它是天貓座中唯一有拜耳名字的恆星[6]。基於視差的觀測,它與地球的距離大約是203光年(62秒差距)[1]。
這是一顆巨星,它耗盡了核心的氫,在演化上已經離開主序帶。它已經膨脹到太陽半徑的55倍,發射的光大約是太陽光度的673倍[7]。估計該恒星外層的有效溫度為3882K[5],低於太陽5778K的有效溫度,使軒轅四呈現橙色的色調,這是K型恒星的特徵[9]。
軒轅四疑似是顆小振幅的紅色變星[10],它的視星等能從+3.17提升至+3.12[11]。這種變化模式通常發生在已經形成惰性碳核並被氦-融合殼層包圍的恆星中,並表明軒轅四正開始演化為米拉型變星[6]。
參考資料
- ^ 1.0 1.1 1.2 1.3 1.4 1.5
van Leeuwen, F. Validation of the new Hipparcos reduction. Astronomy and Astrophysics. 2007, 474 (2): 653–664. Bibcode:2007A&A...474..653V. S2CID 18759600. arXiv:0708.1752
. doi:10.1051/0004-6361:20078357.
- ^ Ducati, J. R. VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system. CDS/ADC Collection of Electronic Catalogues. 2002, 2237. Bibcode:2002yCat.2237....0D.
- ^ Morgan, W. W.; Keenan, P. C. Spectral Classification. Annual Review of Astronomy and Astrophysics. 1973, 11: 29–50. Bibcode:1973ARA&A..11...29M. doi:10.1146/annurev.aa.11.090173.000333.
- ^ 4.0 4.1 4.2 Johnson, H. L.; et al. UBVRIJKL photometry of the bright stars. Communications of the Lunar and Planetary Laboratory. 1966, 4 (1): 99. Bibcode:1966CoLPL...4...99J.
- ^ 5.0 5.1 5.2 5.3 5.4 5.5
Massarotti, A.; et al. Rotational and Radial Velocities for a Sample of 761 HIPPARCOS Giants and the Role of Binarity. The Astronomical Journal. 2008, 135 (1): 209–231. Bibcode:2008AJ....135..209M. doi:10.1088/0004-6256/135/1/209
.
- ^ 6.0 6.1 6.2 6.3 Kaler, J. B. ALPHA LYN (Alpha Lyncis) and ALSCIAUKAT (31 Lyncis). Stars. University of Illinois. 2005-05-11 [2011-12-26]. (原始内容存档于2016-10-18).
- ^ 7.0 7.1 7.2
Piau, L.; et al. Surface convection and red giants radii measurements. Astronomy and Astrophysics. 2010, 526: 100. Bibcode:2011A&A...526A.100P. S2CID 118533297. arXiv:1010.3649
. doi:10.1051/0004-6361/201014442. For Mbol, see Table 1.
- ^ Alpha Lyncis. SIMBAD. 斯特拉斯堡天文資料中心. [2011-12-12].
- ^ The Colour of Stars. Australia Telescope Outreach and Education. Commonwealth Scientific and Industrial Research Organisation. 2004-12-21 [2012-01-16]. (原始内容存档于2012-03-18).
- ^
Percy, J. R.; et al. Photometric surveys of suspected small-amplitude red variables. III: An AAVSO photometric photometry survey. Publications of the Astronomical Society of the Pacific. 1994, 106 (700): 611–615. Bibcode:1994PASP..106..611P. doi:10.1086/133420
.
- ^ Kukarkin, B. V.; et al. Catalogue of suspected variable stars. Nachrichtenblatt der Vereinigung der Sternfreunde E.V. 1981. Bibcode:1981NVS...C......0K.
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