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[3],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[6]。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)[9]

近異雀九(天燕座θ)
近異雀九的位置(紅圈)
觀測資料
曆元 J2000
星座 天燕座
星官
赤經 14h 05m 19.87784s[1]
赤緯 –76° 47′ 48.3204″[1]
視星等(V) 4.65 - 6.20[2]
特性
光譜分類M7 III[3]
U−B 色指數+1.07[4]
B−V 色指數+1.48[4]
變星類型SRb[3] 脈動變星
天體測定
徑向速度 (Rv)+9.0[5] km/s
自行 (μ) 赤經:–83.823 ± 1.302[6] mas/yr
赤緯:–34.694 ± 1.400[6] mas/yr
視差 (π)9.2261 ± 0.6873[6] mas
距離350 ± 30 ly
(108 ± 8 pc)
絕對星等 (MV)0.7[3]
詳細資料
亮度3,879[7] L
溫度3,151[7] K
其他命名
CD–76 615、FK5 1363、HD 122250, HIP 68815、HR 5261、SAO 257112[8]
參考資料庫
SIMBAD資料

它已經演化成為紅巨星,目前在漸近巨星支[10]光譜類型為M7III[3]。它的亮度是太陽的3879倍,表面溫度3151K[11]。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[3];還檢測到超過1,000天的長週期[12]。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)[10]

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[13]

參考資料

編輯
  1. ^ 1.0 1.1 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. 
  2. ^ VSX. [2018-10-29]. (原始內容存檔於2020-08-11). 
  3. ^ 3.0 3.1 3.2 3.3 3.4 3.5 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 . 
  4. ^ 4.0 4.1 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. 
  5. ^ 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 . 
  6. ^ 6.0 6.1 6.2 6.3 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中此天體在蓋亞望遠鏡第二批數據發佈的記錄
  7. ^ 7.0 7.1 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. 
  8. ^ tet Aps -- Semi-regular pulsating Star, SIMBAD (Centre de Données astronomiques de Strasbourg), [2012-07-08], (原始內容存檔於2016-03-04). 
  9. ^ 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. 
  10. ^ 10.0 10.1 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.
  11. ^ 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. 
  12. ^ 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. 
  13. ^ 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.