zh %E5%91%A8%E5%A2%9E%E4%B8%83

**周增七（巨蛇座ι）**
	周增七的位置（紅色圈）
觀測資料; 曆元 J2000
星座	Serpens
星官
赤經	15h 41m 33.05469s
赤緯	19° 40′ 13.4380″
視星等（V）	4.51
特性
光谱分类	B9V + A1V
B−V 色指数	+0.06
天体测定
徑向速度 (Rv)	−17.20 km/s
自行 (μ)	赤经：-60.86 mas/yr ; 赤纬：-43.69 mas/yr
视差 (π)	17.16 ± 0.67 mas
距离	190 ± 7 ly ; (58 ± 2 pc)
绝对星等 (MV)	+0.69
	軌道
繞行週期 (P)	8015.0 days
半長軸 (a)	0.21033"
偏心率 (e)	0.0941
倾斜角 (i)	83.608°
升交点黃經 (Ω)	69.684°
近心點幅角 (ω); (secondary)	80.5°
詳細資料
A
質量	1.999 M☉
B
質量	1.984 M☉
其他命名
	ι Ser、21 Serpentis、BD+20° 3138、GC 21102、HD 140159、HIP 76852、HR 5842、SAO 101682、ADS 9744、CCDM J15416+1940
參考資料庫
SIMBAD	资料

周增七的英文名字來自拉丁文的ι Serpentis，是一顆四合星^[7]，位置在巨蛇座的頭部。它與地球的距離大約是190光年 ^[1]。

系統的中心是一對光譜聯星，周增七A與周增七B。這兩顆都是矮星，並且視星等都是+5.3等。這對聯星的軌道週期有人報告是11年^[8]或22年^[6]。它曾是被發現的第一對天測聯星，但是現在已經得到解決，並且獲得了視覺上的軌道^[6]。

它有兩顆視覺伴星，距離143角秒，視星等13等的周增七C，與距離151角秒，視星等12等的周增七D。

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 [2018-06-28]. Bibcode:2007A&A...474..653V. arXiv:0708.1752 . doi:10.1051/0004-6361:20078357. （原始内容存档于2019-03-28）. Vizier catalog entry （页面存档备份，存于互联网档案馆）
^ ^2.0 ^2.1 ^2.2 Iota Serpentis. SIMBAD Astronomical Database. [2015-10-17].
^ ^3.0 ^3.1 ^3.2 Martin, C; Mignard, F; Hartkopf, W. I; McAlister, H. A. Mass determination of astrometric binaries with Hipparcos. III. New results for 28 systems. Astronomy and Astrophysics Supplement. 1998, 133 (2): 149. Bibcode:1998A&AS..133..149M. doi:10.1051/aas:1998459.
^ Evans, D. S. Batten, Alan Henry; Heard, John Frederick , 编. Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. Determination of Radial Velocities and their Applications 30 (University of Toronto: International Astronomical Union). June 20–24, 1966: 57. Bibcode:1967IAUS...30...57E. 参数|journal=与模板{{cite conference}}不匹配（建议改用{{cite journal}}或|book-title=） (帮助); |contribution=被忽略 (帮助)
^ Anderson, E.; Francis, Ch., XHIP: An extended hipparcos compilation, Astronomy Letters, 2012, 38 (5): 331, Bibcode:2012AstL...38..331A, arXiv:1108.4971 , doi:10.1134/S1063773712050015.
^ ^6.0 ^6.1 ^6.2 Muterspaugh, Matthew W.; et al. The Phases Differential Astrometry Data Archive. II. Updated Binary Star Orbits and a Long Period Eclipsing Binary. The Astronomical Journal. 2010, 140 (6): 1623–1630. Bibcode:2010AJ....140.1623M. arXiv:1010.4043 . doi:10.1088/0004-6256/140/6/1623.
^ 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, arXiv:0806.2878 , doi:10.1111/j.1365-2966.2008.13596.x.
^ van den Bos, W. H. Note on the Double Star Iota Serpentis. Monthly Notes of the Astronomical Society of Southern Africa. 1965, 24: 123. Bibcode:1965MNSSA..24..123V.

这是一篇聯星系統或聚星系統相關的小作品。您可以通过编辑或修订扩充其内容。

[vanLeeuwen2007-1] 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 [2018-06-28]. Bibcode:2007A&A...474..653V. arXiv:0708.1752 . doi:10.1051/0004-6361:20078357. （原始内容存档于2019-03-28）. Vizier catalog entry （页面存档备份，存于互联网档案馆）

[SIMBAD-2] 2.0 ^2.1 ^2.2 Iota Serpentis. SIMBAD Astronomical Database. [2015-10-17].

[martin-3] 3.0 ^3.1 ^3.2 Martin, C; Mignard, F; Hartkopf, W. I; McAlister, H. A. Mass determination of astrometric binaries with Hipparcos. III. New results for 28 systems. Astronomy and Astrophysics Supplement. 1998, 133 (2): 149. Bibcode:1998A&AS..133..149M. doi:10.1051/aas:1998459.

[Evans1967-4] Evans, D. S. Batten, Alan Henry; Heard, John Frederick , 编. Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. Determination of Radial Velocities and their Applications 30 (University of Toronto: International Astronomical Union). June 20–24, 1966: 57. Bibcode:1967IAUS...30...57E. 参数|journal=与模板{{cite conference}}不匹配（建议改用{{cite journal}}或|book-title=） (帮助); |contribution=被忽略 (帮助)

[Anderson2012-5] Anderson, E.; Francis, Ch., XHIP: An extended hipparcos compilation, Astronomy Letters, 2012, 38 (5): 331, Bibcode:2012AstL...38..331A, arXiv:1108.4971 , doi:10.1134/S1063773712050015.

[Muterspaugh2010-6] 6.0 ^6.1 ^6.2 Muterspaugh, Matthew W.; et al. The Phases Differential Astrometry Data Archive. II. Updated Binary Star Orbits and a Long Period Eclipsing Binary. The Astronomical Journal. 2010, 140 (6): 1623–1630. Bibcode:2010AJ....140.1623M. arXiv:1010.4043 . doi:10.1088/0004-6256/140/6/1623.

[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, arXiv:0806.2878 , doi:10.1111/j.1365-2966.2008.13596.x.

[vanDenBos1965-8] van den Bos, W. H. Note on the Double Star Iota Serpentis. Monthly Notes of the Astronomical Society of Southern Africa. 1965, 24: 123. Bibcode:1965MNSSA..24..123V.

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