海石四
觀測資料 曆元 J2000.0 | |
---|---|
星座 | 船底座 |
星官 | |
赤經 | 09h 45m 14.81122s[2] |
赤緯 | –62° 30′ 28.4519″[2] |
視星等(V) | 3.39[3] |
特性 | |
光譜分類 | G5 Iab/Ib[4] |
U−B 色指數 | +0.76[3] |
B−V 色指數 | +1.03[3] |
變星類型 | 經典造父變星 |
天體測定 | |
徑向速度 (Rv) | +3.3[5] km/s |
自行 (μ) | 赤經:–12.88[2] mas/yr 赤緯:+8.19[2] mas/yr |
視差 (π) | 2.09 ± 0.29[2] mas |
距離 | approx. 1,600 ly (approx. 480 pc) |
詳細資料 | |
質量 | 8.4[4] to 13[6] M☉ |
半徑 | ±8 169[7] R☉ |
表面重力 (log g) | 1.5[8] |
溫度 | 5,091[8] K |
金屬量 [Fe/H] | 0.30[8] dex |
年齡 | ±5.9 33.3[4] Myr |
其他命名 | |
海石四(HD 84810),也稱為船底座l (l Car),是位於南天船底座的一顆恆星。它的平均視星等是 +3.4,[3],使它成為船底座較亮,並且以肉眼很容易見到。依據視差測量,它距離地球大約1600光年[2]。
船底座l的光譜類型是G5 Iab/Ib[4],從它的光譜特徵,表明了這顆恆星在演化階段顯示已經膨脹成為一顆超巨星,半徑是太陽的169倍[7]。如果它的質量8倍於太陽[4]–13[6],在主序星經歷了大約1,500-1,700萬年[6],通過燃燒核心供應的核燃料,大約在3,300萬年就會快速的成為超巨星[4]。
船底座l在分類上是一顆造父變星,它的變光幅度是0.725等,週期為35.560天。在每一個脈動週期中徑向速度的改變一致都是39公里/秒[9]。使用干涉儀可以分辨出它有一個緊密的拱星環殼層。使用波長10微米的紅外線可以解析這個殼層,顯示在半徑10-100AU處的平均溫度是100K。這個殼層中的物質是由中心恆星噴發的物質供應[6]。
參考資料
- ^ SIMBAD, "l Carinae", December 30, 2010
- ^ 2.0 2.1 2.2 2.3 2.4 2.5 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, November 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
- ^ 3.0 3.1 3.2 3.3 Madore, B. F., Photoelectric UBV photometry of Cepheids in the Magellanic Clouds and in the southern Milky Way, Astrophysical Journal Supplement Series, June 1975, 29: 219–284, Bibcode:1975ApJS...29..219M, doi:10.1086/190342.
- ^ 4.0 4.1 4.2 4.3 4.4 4.5 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M., A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun, Monthly Notices of the Royal Astronomical Society, January 2011, 410 (1): 190–200, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x.
- ^ Evans, D. S., Batten, Alan Henry; Heard, John Frederick , 編, The Revision of the General Catalogue of Radial Velocities, Determination of Radial Velocities and Their Applications, Proceedings from IAU Symposium No. 30 (University of Toronto: International Astronomical Union), June 20–24, 1966, 30: 57, Bibcode:1967IAUS...30...57E.
- ^ 6.0 6.1 6.2 6.3 Kervella, P.; Mérand, A.; Gallenne, A., The circumstellar envelopes of the Cepheids ℓ Carinae and RS Puppis. Comparative study in the infrared with Spitzer, VLT/VISIR, and VLTI/MIDI, Astronomy and Astrophysics, 2009, 498 (2): 425–443, Bibcode:2009A&A...498..425K, S2CID 14541935, arXiv:0902.1588
, doi:10.1051/0004-6361/200811307.
- ^ 7.0 7.1 Davis, J.; et al, Observations of the pulsation of the Cepheid l Car with the Sydney University Stellar Interferometer, Monthly Notices of the Royal Astronomical Society, April 2009, 394 (3): 1620–1630, Bibcode:2009MNRAS.394.1620D, doi:10.1111/j.1365-2966.2009.14433.x.
- ^ 8.0 8.1 8.2 Luck, R. E., The chemical compositions of nine southern supergiant stars, Astrophysical Journal, Part 1, September 1979, 232: 797–806, Bibcode:1979ApJ...232..797L, doi:10.1086/157340.
- ^ Klagyivik, P.; Szabados, L., Observational studies of Cepheid amplitudes. I. Period-amplitude relationships for Galactic Cepheids and interrelation of amplitudes, Astronomy and Astrophysics, September 2009, 504 (3): 959–972, Bibcode:2009A&A...504..959K, doi:10.1051/0004-6361/200811464.