小熊座π1
小熊座π1[14]是在拱極星座小熊座北部的共同自行聯星[15]。該對的視星等分別為+6.58和+7.31，綜合星等為+6.1[2]。它們位於距離太陽約71光年的地方。兩星的角距離為31.4弧秒[15]，其對應於實際約680AU[16]，並以大約13,100年的週期互繞著彼此運行[9]。
| 观测数据 曆元 J2000.0 分點 J2000.0 (ICRS) | |
|---|---|
| 星座 | 小熊座 |
| 小熊座 π1 A | |
| 赤經 | 15h 29m 11.18599s[1] |
| 赤緯 | +80° 26′ 54.9713″[1] |
| 視星等 (V) | +6.58[2] |
| 小熊座π1 B | |
| 赤經 | 15h 29m 23.59426s[1] |
| 赤緯 | +80° 27′ 00.9675″[1] |
| 視星等 (V) | +7.31[2] |
| 特性 | |
| 光谱分类 | G1.5 V(n)[3] + G9 V[4] |
| U−B 色指数 | +0.13[2] + +0.37[2] |
| B−V 色指数 | +0.67[2] + +0.79[2] |
| 天体测定 | |
| 小熊座π1 A | |
| 徑向速度 (Rv) | −16.27±0.09[5] km/s |
| 自行 (μ) | 赤经：−225.109[6] mas/yr 赤纬：+107.575[6] mas/yr |
| 视差 (π) | 45.8577 ± 0.0328[6] mas |
| 距离 | 71.12 ± 0.05 ly (21.81 ± 0.02 pc) |
| 绝对星等 (MV) | 4.94±0.04[7] |
| π1 UMi B | |
| 徑向速度 (Rv) | −15.40±0.70[5] km/s |
| 自行 (μ) | 赤经：−217.817[8] mas/yr 赤纬：+105.947[8] mas/yr |
| 视差 (π) | 45.8038 ± 0.0352[8] mas |
| 距离 | 71.21 ± 0.05 ly (21.83 ± 0.02 pc) |
| 詳細資料 | |
| 小熊座π1 A | |
| 質量 | 1.02[9] M☉ |
| 半徑 | 0.98[6] R☉ |
| 表面重力 (log g) | 4.40[10] |
| 亮度 | 0.929[6] L☉ |
| 溫度 | 5,771[10] K |
| 金属量 [Fe/H] | −0.22[11] dex |
| 年齡 | 9.22±3.84[12] Gyr |
| π1 UMi B | |
| 質量 | 0.92[9] M☉ |
| 半徑 | 0.84[8] R☉ |
| 表面重力 (log g) | 4.50[10] |
| 亮度 | 0.520[8] L☉ |
| 溫度 | 5,408[10] K |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | π1 UMi AB |
| π1 UMi A | |
| π1 UMi B | |
這兩顆恆星都是類太陽恆星，並已被列為天琴-武仙星協的可能成員，該星協是距離太陽最近的移動星群之一[16]，然而現在認為這不太可能[17]。 主星小熊座π1 A，質量比太陽高2%，表面有效溫度為5,771 K，半徑為太陽的的98%和輻射熱光度為太陽的93%。伴星，小熊座π1 B，質量是太陽的92%，溫度略低為5,408 K，半徑是太陽的 84%，光度略高於太陽的一半。
參考資料
- ^ 1.0 1.1 1.2 1.3 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.
- ^ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Johnson, Harold L., Photoelectric Observations of Visual Double Stars., Astrophysical Journal, May 1953, 117: 361, Bibcode:1953ApJ...117..361J, doi:10.1086/145700.
- ^ Gray, R. O.; et al, Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample, The Astronomical Journal, July 2006, 132 (1): 161–170, Bibcode:2006AJ....132..161G, S2CID 119476992, arXiv:astro-ph/0603770 , doi:10.1086/504637.
- ^ Abt, H. A., Visual multiples. VII - MK classifications, The Astrophysical Journal Supplement Series, 1981, 45: 437, Bibcode:1981ApJS...45..437A, doi:10.1086/190719.
- ^ 5.0 5.1 de Bruijne, J. H. J.; Eilers, A.-C., Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project, Astronomy & Astrophysics, October 2012, 546: 14, Bibcode:2012A&A...546A..61D, S2CID 59451347, arXiv:1208.3048 , doi:10.1051/0004-6361/201219219, A61.
- ^ 6.0 6.1 6.2 6.3 6.4 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天体在盖亚望远镜第二批数据发布的记录
- ^ Porto de Mello, G. F.; et al, A photometric and spectroscopic survey of solar twin stars within 50 parsecs of the Sun; I. Atmospheric parameters and color similarity to the Sun, Astronomy and Astrophysics, March 2014, 563: A52, Bibcode:2014A&A...563A..52P, S2CID 119111150, arXiv:1312.7571 , doi:10.1051/0004-6361/201322277.
- ^ 8.0 8.1 8.2 8.3 8.4 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天体在盖亚望远镜第二批数据发布的记录
- ^ 9.0 9.1 9.2 Tokovinin, Andrei, From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs, The Astronomical Journal, 2014, 147 (4): 14, Bibcode:2014AJ....147...87T, S2CID 56066740, arXiv:1401.6827 , doi:10.1088/0004-6256/147/4/87, 87.
- ^ 10.0 10.1 10.2 10.3 Mishenina, T. V.; et al, Abundances of neutron-capture elements in stars of the Galactic disk substructures, Astronomy & Astrophysics, April 2013, 552: 12, Bibcode:2013A&A...552A.128M, S2CID 119268097, arXiv:1303.1730 , doi:10.1051/0004-6361/201220687, A128.
- ^ Casagrande, L.; et al, New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey, Astronomy & Astrophysics, 2011, 530 (A138): 21, Bibcode:2011A&A...530A.138C, S2CID 56118016, arXiv:1103.4651 , doi:10.1051/0004-6361/201016276.
- ^ Pace, G., Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram, Astronomy & Astrophysics, March 2013, 551: 4, Bibcode:2013A&A...551L...8P, S2CID 56420519, arXiv:1301.5651 , doi:10.1051/0004-6361/201220364, L8.
- ^ ** STF 1972AB. SIMBAD. 斯特拉斯堡天文資料中心. [2017-06-26].
- ^ Kepple, George Robert; Sanner, Glen W., The Night Sky Observers Guide: Spring & summer 2, Willmann-Bell: 418, 1998, ISBN 0943396603.
- ^ 15.0 15.1 Lépine, Sébastien; Bongiorno, Bethany, New Distant Companions to Known Nearby Stars. II. Faint Companions of Hipparcos Stars and the Frequency of Wide Binary Systems, The Astronomical Journal, March 2007, 133 (3): 889–905, Bibcode:2007AJ....133..889L, S2CID 16800796, arXiv:astro-ph/0610605 , doi:10.1086/510333.
- ^ 16.0 16.1 Eisenbeiss, T.; et al, The Hercules-Lyra association revisited. New age estimation and multiplicity study (PDF), Astronomy & Astrophysics, August 2013, 556: 19, Bibcode:2013A&A...556A..53E, S2CID 119275785, arXiv:1312.4045 , doi:10.1051/0004-6361/201118362, A53.[永久失效連結]
- ^ Lopez-Santiago, J.; Montes, D.; Crespo-Chacon, I.; Fernandez-Figueroa, M. J., The Nearest Young Moving Groups, The Astrophysical Journal, 2006, 643 (2): 1160–1165, Bibcode:2006ApJ...643.1160L, S2CID 119520529, arXiv:astro-ph/0601573 , doi:10.1086/503183.
