天街增四

天街增四（金牛座72，縮寫為72 Tau）在黃道星座金牛座，可能是聯星。它的視星等為+5.5，但與較亮的天街增三（金牛座υ）距離只有0.29°，因此裸眼不易看見。依據從地球測得的年周視差7.9mas，它與太陽的距離大約是410光年。 天街增四是一顆光譜為B7V的B型主序星 ，質量為3.48 M☉，和估計年齡約3,800萬年。它的大小是太陽的2.8倍，光度是太陽的185倍。 雖然，這個恆星系統被賦予拜耳名稱 "金牛座υ2"，與"金牛座υ"在天球上的距離只有0.29°。事實上，天街增三（金牛座υ）是一顆前景恒星，兩者不相關，儘管天街增四（金牛座72）位於疏散星團畢宿星團附近，但它離我們很遠。 天街增四位於黃道附近，因此有時會被月球遮蔽。1985年對掩星的觀測表明，它有一顆相距6993484813681109537♠0.1″的伴星。現時還沒有證實這一發現，其他來源仍將這顆恆星列為單星。 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 .  已忽略未知参数|collaboration= (帮助) Gaia DR3 record for this source at VizieR. Høg, E.; et al. The Tycho-2 catalogue of the 2.5 million brightest stars. Astronomy and Astrophysics. 2000, 355: L27–L30. Bibcode:2000A&A...355L..27H.  Mooley, Kunal; et al. B- and A-type Stars in the Taurus-Auriga Star-forming Region. The Astrophysical Journal. July 2013, 771 (2): 24. Bibcode:2013ApJ...771..110M. S2CID 2176170. arXiv:1306.0598 . doi:10.1088/0004-637X/771/2/110. 110.  Hoffleit, D.; Jaschek, C. The Bright Star Catalogue. New Haven: Yale University Observatory. 1991. Bibcode:1991bsc..book.....H.  Gontcharov, G. A. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system. Astronomy Letters. November 2006, 32 (11): 759–771. Bibcode:2006AstL...32..759G. ISSN 1063-7737. S2CID 119231169. arXiv:1606.08053 . doi:10.1134/S1063773706110065.  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.  Freire Ferrero, R.; et al. High Ionization Species in the Nearby Interstellar Medium from an Exhaustive Analysis of the IUE INES Database. The Astronomical Journal. February 2012, 143 (2): 38. Bibcode:2012AJ....143...28F. doi:10.1088/0004-6256/143/2/28 . 28.  Gullikson, Kevin; Kraus, Adam; Dodson-Robinson, Sarah. The Close Companion Mass-ratio Distribution of Intermediate-mass Stars. The Astronomical Journal. 25 July 2016, 152 (2): 40. Bibcode:2016AJ....152...40G. arXiv:1604.06456 . doi:10.3847/0004-6256/152/2/40 . eISSN 1538-3881.  72 Tau. SIMBAD. 斯特拉斯堡天文資料中心.  Kostjuk, N. D. VizieR Online Data Catalog: HD-DM-GC-HR-HIP-Bayer-Flamsteed Cross Index (Kostjuk, 2002). VizieR On-line Data Catalog: IV/27A. Originally Published in: Institute of Astronomy of Russian Academy of Sciences (2002). 2004, 4027. Bibcode:2004yCat.4027....0K.  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 .  已忽略未知参数|collaboration= (帮助) Gaia DR3 record for this source at VizieR. Qian, B. -C; Zhu, G. -L.; Fan, Q. -Y. The measurements of stellar angular diameter by photoelectric observation of lunar occultation. Acta Astronomica Sinica. 1987, 28: 45. Bibcode:1987AcASn..28...39Q.  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.