開陽增一
開陽增一或輔（英語：Alcor /ˈælkɔːr/[9]）是大熊座的一個雙星系統。它是開陽的較暗淡的伴星，兩星共同構成裸眼可辨別的目視雙星，位於北斗七星的柄上。根據依巴谷衛星測量，兩者都位於距離太陽約83光年處。
| 觀測資料 曆元 J2000.0 | |
|---|---|
| 星座 | 大熊座 |
| 星官 | 輔 |
| 赤經 | 13h 25m 13.53783s[1] |
| 赤緯 | +54° 59′ 16.6548″[1] |
| 視星等（V） | +3.99[2] |
| 特性 | |
| 光譜分類 | A5Vn[3] / M3-4[4] |
| 天體測定 | |
| 徑向速度 (Rv) | −9.6[5] km/s |
| 視差 (π) | 39.91 ± 0.13[1] mas |
| 距離 | 81.7 ± 0.3 ly (25.06 ± 0.08 pc) |
| 絕對星等 (MV) | +2.00[2] |
| 詳細資料 | |
| Alcor A | |
| 質量 | 1.84[6] M☉ |
| 半徑 | 1.846[7] R☉ |
| 表面重力 (log g) | 4.25[8] |
| 亮度 | 14.03[6] L☉ |
| 溫度 | 8,221[8] K |
| 自轉速度 (v sin i) | 228[6] km/s |
| Alcor B | |
| 質量 | 0.25[4] M☉ |
| 年齡 | 0.5 ± 0.1[2] Gyr |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 資料 |
命名法
編輯根據佛蘭斯蒂德命名法，開陽增一的名稱為大熊座80（Ursae Majoris 80）。Alcor來自阿拉伯語سها Suhā/Sohā，意為是「被遺忘者」或「被忽略者」，作為開陽的伴星而聞名。[10]
2009年，發現開陽增一的聯星Alcor B，是8.8星等的紅矮星。
2016年，國際天文聯會組織了IAU恆星名稱工作組（WGSN）[11]，對恆星的專名進行分類和標準化。WGSN於2016年7月發佈的第一份公告包含了WGSN批准的首兩批名稱的表格[12]；其中包括大熊座80的西方名Alcor。[13]
參見
編輯參考文獻
編輯- ^ 1.0 1.1 1.2 van Leeuwen, F. Validation of the new Hipparcos reduction. Astronomy and Astrophysics. November 2007, 474 (2): 653–664. Bibcode:2007A&A...474..653V. arXiv:0708.1752
. doi:10.1051/0004-6361:20078357.
- ^ 2.0 2.1 2.2 Mamajek, Eric E.; Kenworthy, Matthew A.; Hinz, Philip M.; Meyer, Michael R. Discovery of a Faint Companion to Alcor Using MMT/AO 5 μm Imaging. The Astronomical Journal. 2010, 139 (3): 919–925. Bibcode:2010AJ....139..919M. arXiv:0911.5028 . doi:10.1088/0004-6256/139/3/919.
- ^ Gray, R. O; Garrison, R. F. The late A-type stars - Refined MK classification, confrontation with Stromgren photometry, and the effects of rotation. Astrophysical Journal Supplement Series. 1989, 70: 623. Bibcode:1989ApJS...70..623G. doi:10.1086/191349.
- ^ 4.0 4.1 Zimmerman, Neil; Oppenheimer, Ben R; Hinkley, Sasha; Brenner, Douglas; Parry, Ian R; Sivaramakrishnan, Anand; Hillenbrand, Lynne; Beichman, Charles; Crepp, Justin R; Vasisht, Gautam; Roberts, Lewis C; Burruss, Rick; King, David L; Soummer, Rémi; Dekany, Richard; Shao, Michael; Bouchez, Antonin; Roberts, Jennifer E; Hunt, Stephanie. Parallactic Motion for Companion Discovery: An M-Dwarf Orbiting Alcor. The Astrophysical Journal. 2010, 709 (2): 733–740. Bibcode:2010ApJ...709..733Z. arXiv:0912.1597 . doi:10.1088/0004-637X/709/2/733.
- ^ Kidger, Mark R; Martín-Luis, Fabiola. High-Precision Near-Infrared Photometry of a Large Sample of Bright Stars Visible from the Northern Hemisphere. The Astronomical Journal. 2003, 125 (6): 3311. Bibcode:2003AJ....125.3311K. doi:10.1086/374996.
- ^ 6.0 6.1 6.2 Zorec, J; Royer, F. Rotational velocities of A-type stars. IV. Evolution of rotational velocities. Astronomy & Astrophysics. 2012, 537: A120. Bibcode:2012A&A...537A.120Z. arXiv:1201.2052 . doi:10.1051/0004-6361/201117691.
- ^ Jones, Jeremy; White, R. J; Boyajian, T; Schaefer, G; Baines, E; Ireland, M; Patience, J; Ten Brummelaar, T; McAlister, H; Ridgway, S. T; Sturmann, J; Sturmann, L; Turner, N; Farrington, C; Goldfinger, P. J. The Ages of A-Stars. I. Interferometric Observations and Age Estimates for Stars in the Ursa Major Moving Group. The Astrophysical Journal. 2015, 813 (1): 58. Bibcode:2015ApJ...813...58J. arXiv:1508.05643 . doi:10.1088/0004-637X/813/1/58.
- ^ 8.0 8.1 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.
- ^ Kunitzsch, Paul; Smart, Tim. A Dictionary of Modern star Names: A Short Guide to 254 Star Names and Their Derivations 2nd rev. Cambridge, Massachusetts: Sky Pub. 2006. ISBN 978-1-931559-44-7.
- ^ Bohigian, George M. An Ancient Eye Test—Using the Stars. Survey of Ophthalmology. 2008, 53 (5): 536–9. PMID 18929764. doi:10.1016/j.survophthal.2008.06.009.
- ^ IAU Working Group on Star Names (WGSN). [22 May 2016]. （原始內容存檔於2020-05-13）.
- ^ Bulletin of the IAU Working Group on Star Names, No. 1 (PDF). [28 July 2016]. （原始內容存檔 (PDF)於2018-04-17）.
- ^ IAU Catalog of Star Names. [28 July 2016]. （原始內容存檔於2018-07-07）.
