论文标题
远离NGT的氢燃烧极限的M型紫外线
An eclipsing M-dwarf close to the hydrogen burning limit from NGTS
论文作者
论文摘要
我们介绍了NGTS J0930-18的发现，这是一种极端的质量比，使M-dwarf二进制系统具有早期的M-dwarf原发性和接近氢燃烧极限的M-dwarf初级和后期的M-dwarf次级。光度法和径向速度的全球建模表明，次级成分（NGTS J0930-18 B）的质量为M = $ 0.0818 ^{+0.0040} _ { - 0.0015} $ $ M _*$ r = $ 0.1059 ^$ 0.1059 ^{+0.1059 ^{+0.0023} _}具有直接质量和半径测量的最低质量恒星的。质量比为Q = $ 0.1407 ^{+0.0065} _ { - 0.017} $，NGTS J0930-18的质量比最低，在任何已知的Eceplips M-Warf二进制系统中，对二进制恒星形成和进化模型提出了有趣的问题。 NGTS J0930-18 B的质量和半径与恒星进化模型一致。 NGTS J0930-18 B位于较少的质量半径参数空间，靠近替代边界。从这种类型的单线黯然失色的二进制系统中对质量和半径进行的精确测量对于限制质量 - 拉迪乌斯关系的不确定性至关重要 - 由于在低质量恒星周围发现的陆地行星数量的增加，因此重要性是重要的。
We present the discovery of NGTS J0930-18, an extreme mass ratio eclipsing M-dwarf binary system with an early M-dwarf primary and a late M-dwarf secondary close to the hydrogen burning limit. Global modelling of photometry and radial velocities reveals that the secondary component (NGTS J0930-18 B) has a mass of M=$0.0818 ^{+0.0040}_{-0.0015}$ $M_*$ and radius of R=$0.1059 ^{+0.0023}_{-0.0021}$ $R_*$, making it one of the lowest mass stars with direct mass and radius measurements. With a mass ratio of q =$0.1407 ^{+0.0065}_{-0.017}$, NGTS J0930-18 has the lowest mass ratio of any known eclipsing M-dwarf binary system, posing interesting questions for binary star formation and evolution models. The mass and radius of NGTS J0930-18 B is broadly consistent with stellar evolutionary models. NGTS J0930-18 B lies in the sparsely populated mass radius parameter space close to the substellar boundary. Precise measurements of masses and radii from single lined eclipsing binary systems of this type are vital for constraining the uncertainty in the mass-radius relationship - of importance due to the growing number of terrestrial planets being discovered around low mass stars.
