水位增十一
水位增十一或巨蟹座12（英語：12 Cancri，縮寫12 Cnc）是黃道十二宮巨蟹座中的一顆恆星。它的視星等為 6.25，[2]略低於在良好視寧條件下肉眼可見恆星的正常極限。從地球軌道觀察，這顆恆星的年視差變化為 12.7 mas，距離地球約 257 光年。它以大約-10公里/秒的徑向速度向太陽移動。[4]
| 觀測資料 曆元 J2000 | |
|---|---|
| 星座 | 巨蟹座 |
| 星官 | |
| 赤經 | 08h 08m 42.4457s[1] |
| 赤緯 | +13° 38′ 27.307″[1] |
| 視星等（V） | 6.25[2] |
| 特性 | |
| 光譜分類 | F3 V[3] |
| B−V 色指數 | 0.480±0.007[2] |
| 天體測定 | |
| 徑向速度 (Rv) | −10.0±4.3[4] km/s |
| 自行 (μ) | 赤經：+2.776[1] mas/yr 赤緯：−14,723[1] mas/yr |
| 視差 (π) | 12.7085 ± 0.1327[1] mas |
| 距離 | 257 ± 3 ly (78.7 ± 0.8 pc) |
| 絕對星等 (MV) | 1.59[5] |
| 詳細資料 | |
| 質量 | 1.16[6] M☉ |
| 表面重力 (log g) | 3.60±0.14[6] |
| 亮度 | 17.94[2] L☉ |
| 溫度 | 6,357±88[7] K |
| 金屬量 [Fe/H] | 0.04[7] dex |
| 自轉速度 (v sin i) | 52.3±4.1[5] km/s |
| 年齡 | 2.466[6] Gyr |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 資料 |
這是一顆普通的F型主序星，恆星分類為F3 V，[3]這表明它的核心通過氫聚變產生能量。它以52[5]公里/秒的預計旋轉速度自轉，似乎正在經歷類似太陽的差異自轉，相對速率α=0.33±0.13。[9]這顆恆星的年齡約為25億歲，[6]質量是太陽的1.16倍，[6]其光球層輻射的光度幾乎是太陽的18倍，[2]有效溫度約為6,357 K。[7]
參考資料
- ^ 1.0 1.1 1.2 1.3 1.4 Vallenari, A.; et al. Gaia Data Release 3. Summary of the content and survey properties. Astronomy & Astrophysics. 2022. arXiv:2208.00211
. doi:10.1051/0004-6361/202243940 . 已忽略未知參數|collaboration=(幫助) Gaia DR3 record for this source at VizieR. - ^ 2.0 2.1 2.2 2.3 2.4 Anderson, E.; Francis, Ch., XHIP: An extended hipparcos compilation, Astronomy Letters, 2012, 38 (5): 331, Bibcode:2012AstL...38..331A, S2CID 119257644, arXiv:1108.4971 , doi:10.1134/S1063773712050015.
- ^ 3.0 3.1 Balachandran, Suchitra, Lithium depletion and rotation in main-sequence stars, Astrophysical Journal, Part 1, May 1, 1990, 354: 310–332, Bibcode:1990ApJ...354..310B, doi:10.1086/168691.
- ^ 4.0 4.1 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.
- ^ 5.0 5.1 5.2 Ammler-von Eiff, Matthias; Reiners, Ansgar, New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?, Astronomy & Astrophysics, June 2012, 542: A116, Bibcode:2012A&A...542A.116A, S2CID 53666672, arXiv:1204.2459 , doi:10.1051/0004-6361/201118724.
- ^ 6.0 6.1 6.2 6.3 6.4 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, S2CID 33401607, arXiv:1501.03154 , doi:10.1088/0004-637X/804/2/146.
- ^ 7.0 7.1 7.2 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 and Astrophysics, June 2011, 530: A138, Bibcode:2011A&A...530A.138C, S2CID 56118016, arXiv:1103.4651 , doi:10.1051/0004-6361/201016276.
- ^ 12 Cnc. SIMBAD. 斯特拉斯堡天文資料中心.
- ^ Reiners, Ansgar; Schmitt, Jürgen H. M. M., Differential rotation in rapidly rotating F-stars, Astronomy and Astrophysics, December 2003, 412 (3): 813−819, Bibcode:2003A&A...412..813R, S2CID 16900202, arXiv:astro-ph/0309616 , doi:10.1051/0004-6361:20034255.
