zh %E6%B0%B4%E4%BD%8D%E5%A2%9E%E4%B8%83

**水位增七**
觀測資料; 曆元 J2000.0
星座	巨蟹座
星官
赤經	08h 00m 47.30744s
赤緯	+17° 18′ 31.3283″
視星等（V）	5.60
特性
光谱分类	K3 III
B−V 色指数	1.317
天体测定
徑向速度 (Rv)	+39.55±0.16 km/s
自行 (μ)	赤经：−10.403 mas/yr ; 赤纬：−3.905 mas/yr
视差 (π)	4.0087 ± 0.1511 mas
距离	810 ± 30 ly ; (249 ± 9 pc)
绝对星等 (MV)	−1.29
詳細資料
質量	2.9 M☉
半徑	40 R☉
表面重力 (log g)	2.05
亮度	568.61 L☉
溫度	4,300 K
自轉速度 (v sin i)	5.73 km/s
其他命名
	3 Cnc、BD+17°1731、FK5 2618、HD 65759、HIP 39177、HR 3128、SAO 97472
參考資料庫
SIMBAD	资料

水位增七或巨蟹座3（英语：3 Cancri，缩写3 Cnc）是巨蟹座中的一颗恒星，^[7]距离太阳约810光年。它是一颗暗淡的橙色恒星，肉眼可见，视星等为5.60。^[2]该天体正以+39.5 km/s^[1]的日心径向速度远离地球，可能是毕宿星团的成员。^[8]它位于黄道附近，因此容易发生月食。^[9]

这是一颗老化的巨星，恒星分类为K3 III，^[3]最有可能（86%的可能性）位于水平分支上。^[5]这颗恒星的质量是太阳的2.9倍，并且已经膨胀到太阳半径的40倍。^[5]它的扩大光球层的有效温度为4,300 K，^[4]辐射出的光度是太阳光度的569倍。^[2]

行星系

在2020年，利用径向速度法在一条非常轻微偏心的轨道上探测到了一颗围绕水位增七运行的超级木星系外行星，即巨蟹座3b。^[10]

水位增七的行星系^[11]
成員 (依恆星距離)	质量	半長軸 (AU)	轨道周期 (天)	離心率	傾角	半径
b	20.76 M_J	2.52	853.64	0.4	—	—

参见

参考资料

^ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 ^1.6 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
^ ^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 Adams, Walter S.; et al, The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars, Astrophysical Journal, 1935, 81: 187, Bibcode:1935ApJ....81..187A, doi:10.1086/143628 
^ ^4.0 ^4.1 ^4.2 ^4.3 ^4.4 Hekker, S.; Meléndez, J., Precise radial velocities of giant stars. III. Spectroscopic stellar parameters, Astronomy and Astrophysics, 2007, 475 (3): 1003–1009, Bibcode:2007A&A...475.1003H, S2CID 10436552, arXiv:0709.1145 , doi:10.1051/0004-6361:20078233.
^ ^5.0 ^5.1 ^5.2 ^5.3 Stock, S.; et al, Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search, Astronomy & Astrophysics, August 2018, 616: 15, Bibcode:2018A&A...616A..33S, S2CID 119361866, arXiv:0709.1145 , doi:10.1051/0004-6361/201833111, A33.
^ 3 Cnc. SIMBAD. 斯特拉斯堡天文資料中心.
^ Eggleton, P. P.; Tokovinin, A. A., A catalogue of multiplicity among bright stellar systems, Monthly Notices of the Royal Astronomical Society, September 2008, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, S2CID 14878976, arXiv:0806.2878 , doi:10.1111/j.1365-2966.2008.13596.x.
^ Eggen, O. J., The red giants in the Hyades group, Publications of the Astronomical Society of the Pacific, June 1972, 84: 406, Bibcode:1972PASP...84..406E, doi:10.1086/129303 .
^ White, Nathaniel M.; Feierman, Barry H., A Catalog of Stellar Angular Diameters Measured by Lunar Occultation, Astronomical Journal, September 1987, 94: 751, Bibcode:1987AJ.....94..751W, doi:10.1086/114513.
^ Pinto, Marcelo Tala; Reffert, Sabine; Quirrenbach, Andreas; Stock, Stephan; Trifonov, Trifon; Mitchell, David S. Precise radial velocities of giant stars. Astronomy & Astrophysics. 2020, 644: A1. doi:10.1051/0004-6361/202038285. hdl:10150/622444 .
^ The Extrasolar Planet Encyclopaedia — 3 Cnc b. exoplanet.eu. [2021-04-29]. （原始内容存档于2023-07-10）.

[GaiaDR2-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 ^1.6 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

[Anderson2012-2] 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.

[Adams1935-3] 3.0 ^3.1 Adams, Walter S.; et al, The Spectroscopic Absolute Magnitudes and Parallaxes of 4179 Stars, Astrophysical Journal, 1935, 81: 187, Bibcode:1935ApJ....81..187A, doi:10.1086/143628 

[Hekker2007-4] 4.0 ^4.1 ^4.2 ^4.3 ^4.4 Hekker, S.; Meléndez, J., Precise radial velocities of giant stars. III. Spectroscopic stellar parameters, Astronomy and Astrophysics, 2007, 475 (3): 1003–1009, Bibcode:2007A&A...475.1003H, S2CID 10436552, arXiv:0709.1145 , doi:10.1051/0004-6361:20078233.

[Stock2018-5] 5.0 ^5.1 ^5.2 ^5.3 Stock, S.; et al, Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search, Astronomy & Astrophysics, August 2018, 616: 15, Bibcode:2018A&A...616A..33S, S2CID 119361866, arXiv:0709.1145 , doi:10.1051/0004-6361/201833111, A33.

[SIMBAD-6] 3 Cnc. SIMBAD. 斯特拉斯堡天文資料中心.

[Eggleton2008-7] Eggleton, P. P.; Tokovinin, A. A., A catalogue of multiplicity among bright stellar systems, Monthly Notices of the Royal Astronomical Society, September 2008, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, S2CID 14878976, arXiv:0806.2878 , doi:10.1111/j.1365-2966.2008.13596.x.

[Eggen1972-8] Eggen, O. J., The red giants in the Hyades group, Publications of the Astronomical Society of the Pacific, June 1972, 84: 406, Bibcode:1972PASP...84..406E, doi:10.1086/129303 .

[White1987-9] White, Nathaniel M.; Feierman, Barry H., A Catalog of Stellar Angular Diameters Measured by Lunar Occultation, Astronomical Journal, September 1987, 94: 751, Bibcode:1987AJ.....94..751W, doi:10.1086/114513.

[Pinto2020-10] Pinto, Marcelo Tala; Reffert, Sabine; Quirrenbach, Andreas; Stock, Stephan; Trifonov, Trifon; Mitchell, David S. Precise radial velocities of giant stars. Astronomy & Astrophysics. 2020, 644: A1. doi:10.1051/0004-6361/202038285. hdl:10150/622444 .

[auto-11] The Extrasolar Planet Encyclopaedia — 3 Cnc b. exoplanet.eu. [2021-04-29]. （原始内容存档于2023-07-10）.

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