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[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]。
  | |
| 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 | |
| 光谱分类 | M7 III[3] |
| U−B 色指数 | +1.07[4] |
| B−V 色指数 | +1.48[4] |
| 变星类型 | SRb[3] 脈動變星 |
| 天体测定 | |
| 徑向速度 (Rv) | +9.0[5] km/s |
| 自行 (μ) | 赤经：–83.823 ± 1.302[6] mas/yr 赤纬：–34.694 ± 1.400[6] mas/yr |
| 视差 (π) | 9.2261 ± 0.6873[6] mas |
| 距离 | 350 ± 30 ly (108 ± 8 pc) |
| 绝对星等 (MV) | 0.7[3] |
| 詳細資料 | |
| 亮度 | 3,879[7] L☉ |
| 溫度 | 3,151[7] K |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 资料 |
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]。
參考資料
- ^ 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.
- ^ VSX. [2018-10-29]. （原始内容存档于2020-08-11）.
- ^ 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 .
- ^ 4.0 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.
- ^ 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 .
- ^ 6.0 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中此天体在盖亚望远镜第二批数据发布的记录
- ^ 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.
- ^ 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.
- ^ 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.
- ^ 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.
