HD 49798
| 观测资料 历元 J2000 | |
|---|---|
| 星座 | 船尾座 |
| 星官 | |
| 赤经 | 06h 48m 04.69996s[1] |
| 赤纬 | −44° 18′ 58.4377″[1] |
| 视星等（V） | 8.287[2] |
| 特性 | |
| 光谱分类 | sdO6p |
| U−B 色指数 | −1.259[2] |
| B−V 色指数 | −0.270[2] |
| 变星类型 | 高质量X射线联星（HMXB）[3] |
| 天体测定 | |
| 径向速度 (Rv) | 12.10[4] km/s |
| 自行 (μ) | 赤经：−4.73[1] mas/yr 赤纬：5.39[1] mas/yr |
| 视差 (π) | 1.20 ± 0.50[1] mas |
| 距离 | 650[3] pc |
| 轨道[3] | |
| 绕行周期 (P) | 1.55天 |
| 偏心率 (e) | 0.0 |
| 倾斜角 (i) | 82° |
| 详细资料 | |
| sdO5.5[5] | |
| 质量 | 1.50[3] M☉ |
| 半径 | 1.45[6] R☉ |
| 表面重力 (log g) | 4.25[6] |
| 亮度 | 3,943[6] L☉ |
| 温度 | 47,500[6] K |
| WD | |
| 质量 | 1.28[3] M☉ |
| 其他命名 | |
| 参考资料库 | |
| SIMBAD | 资料 |
HD 49798是在船尾座的一颗联星，距离地球大约650秒差距。它的视星等为 +8.3等。
HD 49798是在1964年被发现是一颗罕见的，欠缺氢融合的O型次矮星[7]。它被认定是联星，但是始终未能目视或从光谱检测出其伴星[8]。
在它的附近，科学家发现了X射线源，并标示为RX J0648.0-4418。但是只有XMM-牛顿卫星太空望远镜能够识别发出这个辐射的天体。它是一颗质量约为1.3太阳质量白矮星，在轨道上以13秒的周期环绕著HD 49798[9]。这一系统被认为是超新星的候选者，在数千年后可能爆炸成为Ia型超新星 [10][11]。
参考资料[编辑]
- ^ 1.0 1.1 1.2 1.3 1.4 Van Leeuwen, F. Validation of the new Hipparcos reduction. Astronomy and Astrophysics. 2007, 474 (2): 653. Bibcode:2007A&A...474..653V. arXiv:0708.1752
. doi:10.1051/0004-6361:20078357.
- ^ 2.0 2.1 2.2 Landolt, Arlo U.; Uomoto, Alan K. Optical Multicolor Photometry of Spectrophotometric Standard Stars. The Astronomical Journal. 2007, 133 (3): 768. Bibcode:2007AJ....133..768L. arXiv:0704.3030 . doi:10.1086/510485.
- ^ 3.0 3.1 3.2 3.3 3.4 Mereghetti, S.; La Palombara, N.; Tiengo, A.; Sartore, N.; Esposito, P.; Israel, G. L.; Stella, L. X-ray emission from the luminous O-type subdwarf HD 49798 and its compact companion. Astronomy & Astrophysics. 2013, 553: A46. Bibcode:2013A&A...553A..46M. arXiv:1304.1653 . doi:10.1051/0004-6361/201321271.
- ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. SB9: The ninth catalogue of spectroscopic binary orbits. Astronomy and Astrophysics. 2004, 424 (2): 727. Bibcode:2004A&A...424..727P. arXiv:astro-ph/0406573 . doi:10.1051/0004-6361:20041213.
- ^ Mereghetti, S.; Tiengo, A.; Esposito, P.; La Palombara, N.; Israel, G. L.; Stella, L. An Ultramassive, Fast-Spinning White Dwarf in a Peculiar Binary System. Science. 2009, 325 (5945): 1222. Bibcode:2009Sci...325.1222M. PMID 19729650. arXiv:1003.0997 . doi:10.1126/science.1176252.
- ^ 6.0 6.1 6.2 6.3 Kudritzki, R. P.; Simon, K. P. Non-LTE analysis of subluminous O-star. The hydrogen-deficient subdwarf O-binary HD 49798. Astronomy and Astrophysics. 1978, 70: 653. Bibcode:1978A&A....70..653K.
- ^ Jaschek, Mercedes; Jaschek, Carlos. HD 49798, a New O-Type Subdwarf. Publications of the Astronomical Society of the Pacific. 1963, 75: 365. Bibcode:1963PASP...75..365J. doi:10.1086/127968.
- ^ Thackeray, A. D. The spectroscopic orbit of the O-type subdwarf HD 49798. Monthly Notices of the Royal Astronomical Society. 1970, 150 (2): 215. Bibcode:1970MNRAS.150..215T. doi:10.1093/mnras/150.2.215.
- ^ Bisscheroux, B. C.; Pols, O. R.; Kahabka, P.; Belloni, T.; Van Den Heuvel, E. P. J. The nature of the bright subdwarf HD 49798 and its X-ray pulsating companion. Astronomy and Astrophysics. 1997, 317: 815. Bibcode:1997A&A...317..815B.
- ^ Wang, Bo; Han, Zhanwen. Progenitors of type Ia supernovae. New Astronomy Reviews. 2012, 56 (4): 122. Bibcode:2012NewAR..56..122W. arXiv:1204.1155 . doi:10.1016/j.newar.2012.04.001.
- ^ Liu, Dong-Dong; Zhou, Wei-Hong; Wu, Cheng-Yuan; Wang, Bo. Is the X-ray pulsating companion of HD 49798 a possible type Ia supernova progenitor?. Research in Astronomy and Astrophysics. 2015, 15 (11): 1813. Bibcode:2015RAA....15.1813L. arXiv:1504.01461 . doi:10.1088/1674-4527/15/11/004.
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