獵犬座DG
獵犬座DG是以變星命名的聯星[2],這個系統位於北天的獵犬座。在2009年,這一對的角距離是0.20角秒,方位角為285°,對應於實際的距離大約是3.6天文單位[7],視星等12.02等,是太微弱了,以至於裸眼看不見它們[2]。視差測量這一對系統與地球的距離大約是59光年[2]。
主星的恆星光譜為M4.0Ve,表示這是顆有發射譜線的紅矮星。它被認為是非常年輕的系統,估計年齡只有3,000萬歲[7],並有著比太陽高的金屬量[6]。主星的自轉非常快速,投射轉速高達每秒50公里[2]。系統中至少有一顆是閃光星的變星,這意味著它的亮度會隨機地進行短暫增加。在2014年4月23日,史威福衛星觀察到這個系統所在位置的伽瑪射線超級閃焰事件;這也許是在紅矮星上觀察到的最耀眼事件。在一天後,觀察到第二個電波閃焰[7]。
參考資料
- ^ 1.0 1.1 Høg, E.; et al, The Tycho-2 catalogue of the 2.5 million brightest stars, Astronomy and Astrophysics, March 2000, 355: L27–L30, Bibcode:2000A&A...355L..27H, ISBN 0333750888, doi:10.1888/0333750888/2862.
- ^ 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 Riedel, Adric R.; et al, The Solar Neighborhood. XXXIII. Parallax Results from the CTIOPI 0.9 m Program: Trigonometric Parallaxes of Nearby Low-mass Active and Young Systems, The Astronomical Journal, 2014, 147 (4): 85, Bibcode:2014AJ....147...85R, arXiv:1401.0722 , doi:10.1088/0004-6256/147/4/85.
- ^ Samus, N. N.; Durlevich, O. V.; et al. VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013). VizieR On-line Data Catalog: B/gcvs. Originally published in: 2009yCat....102025S. 2009, 1. Bibcode:2009yCat....102025S.
- ^ Cortés-Contreras, M; Béjar, V. J. S; Caballero, J. A; Gauza, B; Montes, D; Alonso-Floriano, F. J; Jeffers, S. V; Morales, J. C; Reiners, A; Ribas, I; Schöfer, P; Quirrenbach, A; Amado, P. J; Mundt, R; Seifert, W. CARMENES input catalogue of M dwarfs. II. High-resolution imaging with Fast Cam. Astronomy & Astrophysics. 2017, 597: A47. Bibcode:2017A&A...597A..47C. arXiv:1608.08145 . doi:10.1051/0004-6361/201629056.
- ^ 5.0 5.1 5.2 Houdebine, E. R; Mullan, D. J; Paletou, F; Gebran, M. Rotation-Activity Correlations in K and M Dwarfs. I. Stellar Parameters and Compilations of v sin i and P/sin i for a Large Sample of Late-K and M Dwarfs. The Astrophysical Journal. 2016, 822 (2): 97. Bibcode:2016ApJ...822...97H. arXiv:1604.07920 . doi:10.3847/0004-637X/822/2/97.
- ^ 6.0 6.1 Newton, Elisabeth R.; et al, Near-infrared Metallicities, Radial Velocities, and Spectral Types for 447 Nearby M Dwarfs, The Astronomical Journal, January 2014, 147 (1): 24, Bibcode:2014AJ....147...20N, arXiv:1310.1087 , doi:10.1088/0004-6256/147/1/20, 20.
- ^ 7.0 7.1 7.2 7.3 7.4 Fender, R. P.; et al, A prompt radio transient associated with a gamma-ray superflare from the young M dwarf binary DG CVn, Monthly Notices of the Royal Astronomical Society: Letters, January 2015, 446 (1): L66–L70, Bibcode:2015MNRAS.446L..66F, arXiv:1410.1545 , doi:10.1093/mnrasl/slu165.
- ^ DG CVn -- Flare Star, SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), [2016-03-11], (原始内容存档于2017-01-08).
外部連結
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