天苑增三

天炉座α（α Fornacis, α For）是天炉座最亮的恒星，但只比4等星亮一点。中国传统名天苑增三^[9]，它在西洋的固有名称是Dalim （出自皮亚齐的星表Palermo Catalogue（英语：Palermo Catalogue））^[10][11][12]和Fornacis（在Burritt（英语：Elijah Hinsdale Burritt）的星图）^[13]。这颗恒星最初的名称是 波江座12。

天炉座α

天炉座α的位置（左上）
观测资料 历元 J2000
星座	天炉座
星官	天苑（昴宿）
赤经	3h 12m 04.5277s[1]
赤纬	–28° 59′ 15.425″[1]
视星等（V）	3.85[2]
特性
光谱分类	F8IV[3]
U−B 色指数	+0.082[4]
B−V 色指数	+0.581[4]
天体测定
径向速度 (Rv)	–20.5[5] km/s
自行 (μ)	赤经：371.49[1] mas/yr 赤纬：612.28[1] mas/yr
视差 (π)	70.24 ± 0.45[1] mas
距离	46.4 ± 0.3 ly (14.24 ± 0.09 pc)
详细资料
质量	1.33 ± 0.01[6] M☉
半径	2.04 ± 0.06[7] R☉
表面重力 (log g)	4.27[6]
亮度	4.87 ± 0.16[7] L☉
温度	6,240[6] K
金属量 [Fe/H]	–0.20[6] dex
自转速度 (v sin i)	3.9[7] km/s
年龄	2.9[8] Gyr
其他命名
12 Eridani, CD-29 1177, GJ 127, HD 20010, HIP 14879, HR 963, LTT 1512, SAO 168373.[2]
参考数据库
SIMBAD	资料

天炉座α的光谱类型是F8IV，其中的IV表示它的亮度是在演化上已经离开主序星的次巨星^[14]。它的质量比太阳重约33%，年龄是29亿岁^[6][8]。天炉座α是一对联星 ^[15]，有着高自行运动^[2]。这个系统显示出红外过量，暗示可能有类似岩屑盘的拱星盘^[16]

第二颗恒星已经被确认是颗蓝掉队星，它可能是合并了之前存在的第三颗恒星，或是累积了它的物质。它是个强X射线源，质量约为太阳的78% ^[17]。

这颗恒星的空间速度元件是（U、 V、 W） = （–35，+ 20，+ 30）km/s^[18]。大约35万年前，天炉座α星曾于A型主序星的时钟座ν有过一次亲密的接触。估计曾互相接近至0.265 ly（0.081 pc）的距离，使这两颗恒星都有岩屑盘^[19]。

参考资料

1. Perryman, M. A. C.; et al. The HIPPARCOS Catalogue. Astronomy & Astrophysics. April 1997, 323: L49–L52. Bibcode:1997A&A...323L..49P.
2. LHS 1515 -- High proper-motion Star. SIMBAD. Centre de Données astronomiques de Strasbourg. [2010-05-10]. （原始内容存档于2016-04-13）.
3. Favata, F.; Micela, G.; Sciortino, S. The [Fe/H] distribution of a volume limited sample of solar-type stars and its implications for galactic chemical evolution.. Astronomy and Astrophysics. July 1997, 323: 809–818. Bibcode:1997A&A...323..809F.
4. Rakos, K. D.; et al. Photometric and astrometric observations of close visual binaries. Astronomy and Astrophysics Supplement Series. February 1982, 47: 221–235. Bibcode:1982A&AS...47..221R.
5. Evans, D. S. The Revision of the General Catalogue of Radial Velocities. Batten, Alan Henry; Heard, John Frederick (编). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. June 20–24, 1966 [2009-09-10]. Bibcode:1967IAUS...30...57E. （原始内容存档于2019-06-26）.
6. Santos, N. C.; Israelian, G.; Mayor, M. The metal-rich nature of stars with planets. Astronomy and Astrophysics. July 2001, 373 (3): 1019–1031. Bibcode:2001A&A...373.1019S. arXiv:astro-ph/0105216 . doi:10.1051/0004-6361:20010648.
7. Bruntt, H.; et al, Accurate fundamental parameters for 23 bright solar-type stars, Monthly Notices of the Royal Astronomical Society, July 2010, 405 (3): 1907–1923, Bibcode:2010MNRAS.405.1907B, arXiv:1002.4268 , doi:10.1111/j.1365-2966.2010.16575.x
8. Nordström, B.; Mayor, M.; Andersen, J.; Holmberg, J.; Pont, F.; Jørgensen, B. R.; Olsen, E. H.; Udry, S.; Mowlavi, N. The Geneva-Copenhagen survey of the Solar neighbourhood. Ages, metallicities, and kinematic properties of ˜14 000 F and G dwarfs. Astronomy and Astrophysics. May 2004, 418 (3): 989–1019. Bibcode:2004A&A...418..989N. arXiv:astro-ph/0405198 . doi:10.1051/0004-6361:20035959. See VizierR catalogue V/130 （页面存档备份，存于互联网档案馆）.
9. 伊世同 《中西对照恒星图表》
10. Piazzi, G (编). Praecipuarum Stellarum Inerrantium Positiones Mediae Ineunte Saeculo XIX: ex Observationibus Habitis in Specula Panormitana ab anno 1792 ad annum 1813. Palermo. 1814: 21.
11. Kunitzsch, P. Arabische Sternnamen in Europa. Wiesbaden: Otto Harrassowitz. 1959: 155.
12. Laffitte, R. Héritages arabes: Des noms arabes pour les étoiles 2^éme revue et corrigée. Paris: Librairie Orientaliste Paul Geunthner / Les Cahiers de l'Orient. 2005: 229.
13. Burritt, E. H. Atlas, Designed to Illustrate the Geography of the Heavens new. New York: F. J. Huntington. 1835. plate III.
14. Lopez, Bruno; Schneider, Jean; Danchi, William C. Can Life Develop in the Expanded Habitable Zones around Red Giant Stars?. The Astrophysical Journal. July 2005, 627 (2): 974–985. Bibcode:2005ApJ...627..974L. arXiv:astro-ph/0503520 . doi:10.1086/430416.
15. Söderhjelm, Staffan. Visual binary orbits and masses POST HIPPARCOS. Astronomy and Astrophysics. January 1999, 341: 121–140. Bibcode:1999A&A...341..121S.
16. Oudmaijer, Rene D.; et al. SAO stars with infrared excess in the IRAS Point Source Catalog. Astronomy and Astrophysics Supplement Series. December 1992, 96 (3): 625–643. Bibcode:1992A&AS...96..625O.
17. Fuhrmann, K.; Chini, R., Multiplicity among F-type Stars. II, The Astrophysical Journal, August 2015, 809 (1): 19, Bibcode:2015ApJ...809..107F, doi:10.1088/0004-637X/809/1/107, 107.
18. Gliese, W. Catalogue of Nearby Stars. Veröffentlichungen des Astronomischen Rechen-Instituts Heidelberg. 1969. Bibcode:1969VeARI..22....1G.
19. Deltorn, J.-M.; Kalas, P. Search for Nemesis Encounters with Vega, ε Eridani, and Fomalhaut. Ray Jayawardhana; Thomas Greene (编). Young Stars Near Earth: Progress and Prospects. ASP Conference Series 244. San Francisco: Astronomical Society of the Pacific: 227. 2001. Bibcode:2001ASPC..244..227D. ISBN 1-58381-082-X.

外部链接

• α For (Dalim)（页面存档备份，存于互联网档案馆） - SKY-MAP.ORG（页面存档备份，存于互联网档案馆）
• LHL Digital Collections（页面存档备份，存于互联网档案馆） - Linda Hall library（页面存档备份，存于互联网档案馆）