X-ray emission from the ultracool dwarf LHS 2065
X-ray emission from the ultracool dwarf LHS 2065
复制标题
超冷矮星 LHS 2065 发出的 X 射线
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
C. Liefke
中科院分区：
文献类型：
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作者：
J. H. M. M. Schmitt;C. Liefke
本文报道了用ROSAT高分辨率成像仪（HRI）对M9V超冷矮星LHS 2065进行68 ks长的x射线观测的结果。在观测期间发生了一次主要的x射线耀斑，其峰值x射线光度为$4 × 10^{31}$ erg/s，总软能量释放为$2 × 10^{31}$ erg。此外，还发生了另一个峰值x射线光度和能量释放较小的耀斑。x射线观测间隔半年进行。在观测的前半部分，LHS 2065没有明显的x射线发射，而在后半段，除了耀斑外，还观察到2.3倍10^{26}$ erg/s的静止x射线发射。LHS 2065属于已知温度最低的氢燃烧恒星。ROSAT的观测表明，即使在这种非常晚类型的恒星中，日冕辐射也可能相当普遍。
We report the results of a 68 ks long X-ray observation of the M9V ultracool dwarf star LHS 2065 with the ROSAT high resolution imager (HRI). During the observations a major X-ray flare occurred with a peak X-ray luminosity of $4 imes 10^{27}$ erg/s and a total soft energy release of $2 imes 10^{31}$ erg. In addition, another flare with smaller peak X-ray luminosity and energy release occurred. The X-ray observations were carried out half a year apart. In the first half of the observations no significant X-ray emission from LHS 2065 could be detected, while in the second half in addition to flares also quiescent X-ray emission at a level of $2.3 imes 10^{26}$ erg/s was seen. LHS 2065 belongs to the coolest hydrogen burning stars known. The ROSAT observations show that coronal emission may be quite common even among such very late-type stars.