近異雀九

近異雀九 （天燕座θ）是在南天拱極星座天燕座中的一顆恆星。它是一顆變星，視星等在+4.65至+6.20之間變化，依據波特爾暗空分類法的分級，這是一顆暗弱的恆星，要在黑暗的郊區天空中才能以裸眼看見。根據蓋亞望遠鏡的視差測量，它與地球的距離是350光年（110秒差距）。不尋常的是，它是一顆紅星，並且有極高的自行（超過每年50毫秒）。 它已經演化成為紅巨星，目前在漸近巨星支，光譜類型為M7III。它的亮度是太陽的3879倍，表面溫度3151K。它是一顆半規則的脈動變星，變光幅度超過0.56等，週期為119天；還檢測到超過1,000天的長週期。它通過恆星風，以每年1.1 × 10−7太陽質量的速率流失質量。從這顆恆星噴出的塵埃物質與周圍的星際物質作用，在穿越銀河系時形成艏震波。波的前緣距離近異雀九大約0.134 ly（0.041 pc）。 近異雀九已被確定為聯星，表明它有一顆軌道上的伴星，導致主星受到攝動。 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, November 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752 , doi:10.1051/0004-6361:20078357.  VSX. [2018-10-29]. （原始内容存档于2020-08-11）.  Yeşilyaprak, C.; Aslan, Z., Period-luminosity relation for M-type semiregular variables from Hipparcos parallaxes, Monthly Notices of the Royal Astronomical Society, December 2004, 355 (2): 601–607, Bibcode:2004MNRAS.355..601Y, doi:10.1111/j.1365-2966.2004.08344.x .  Wisse, P. N. J., Three colour observations of southern red variable giant stars, Astronomy and Astrophysics Supplement Series, May 1981, 44: 273–303, Bibcode:1981A&AS...44..273W.  Feast, M. W.; Woolley, R.; Yilmaz, N., The kinematics of semi-regular red variables in the solar neighbourhood, Monthly Notices of the Royal Astronomical Society, 1972, 158: 23–46, Bibcode:1972MNRAS.158...23F, doi:10.1093/mnras/158.1.23 .  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 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. Fundamental parameters and infrared excesses of Hipparcos stars. Monthly Notices of the Royal Astronomical Society. 2012, 427 (1): 343. Bibcode:2012MNRAS.427..343M. arXiv:1208.2037 . doi:10.1111/j.1365-2966.2012.21873.x.  tet Aps -- Semi-regular pulsating Star, SIMBAD (Centre de Données astronomiques de Strasbourg), [2012-07-08], （原始内容存档于2016-03-04）.  Jiménez-Esteban, F. M.; Caballero, J. A.; Dorda, R.; Miles-Páez, P. A.; Solano, E. Identification of red high proper-motion objects in Tycho-2 and 2MASS catalogues using Virtual Observatory tools. Astronomy & Astrophysics. 2012, 539: 12. Bibcode:2012A&A...539A..86J. arXiv:1201.5315 . doi:10.1051/0004-6361/201118375.  Cox, N. L. J.; et al, A far-infrared survey of bow shocks and detached shells around AGB stars and red supergiants, Astronomy & Astrophysics, January 2012, 537: A35, Bibcode:2012A&A...537A..35C, arXiv:1110.5486 , doi:10.1051/0004-6361/201117910.  See table 1, IRAS 14003-7633. McDonald, I.; Zijlstra, A. A.; Boyer, M. L. Fundamental Parameters and Infrared Excesses of Hipparcos Stars. Monthly Notices of the Royal Astronomical Society. 2012, 427 (1): 343–57. Bibcode:2012MNRAS.427..343M. arXiv:1208.2037 . doi:10.1111/j.1365-2966.2012.21873.x.  Moon, T. T. Combining Visual and Photoelectric Observations of Semiregular Red Variables. Journal of the American Association of Variable Star Observers. 2008, 36 (1): 77. Bibcode:2008JAVSO..36...77M.  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.