论文标题
$γ$ Columbae：最近剥离的，巨大的恒星的脉动核心
$γ$ Columbae: the recently stripped, pulsating core of a massive star
论文作者
论文摘要
地球生命的至关重要的条件是太阳稳定地供应辐射热。像所有其他恒星一样，太阳在其中央区域产生发射的能量，那里的密度和温度足够高，可以进行核融合过程。由于恒星核心通常被不透明的包膜覆盖，因此我们对它们及其赋予生命的核过程的大多数知识来自理论建模或间接观察结果，例如对太阳中微子的检测和对恒星脉动的研究。只有在极少数情况下，恒星才能暴露其岩心，例如，当它们的一小部分演变成狼射线或氦气热分子恒星时。但是，对于绝大多数恒星，即未发展的恒星，它们的中心将氢燃烧到氦气中，岩心上的直接观察线索仍然缺失。 Based on a comprehensive spectroscopic and asteroseismic analysis, we show here that the bright B-type star $γ$ Columbae is the stripped pulsating core (with a mass of $4$-$5\,M_\odot$, where $M_\odot$ is the mass of the Sun) of a previously much more massive star of roughly $12\,M_\odot$ that just finished central hydrogen fusion.恒星的推断参数表明它仍处于短暂的插图后结构调整阶段，使其成为极为罕见的对象。这个独特的恒星的发现铺平了道路，以获取有关核天体物理学和共同嵌入式进化的单颗恒星物理学的宝贵见解。特别是，它对被剥离的包络恒星的结构和演变提供了第一个观察性约束。
A vital condition for life on Earth is the steady supply of radiative heat by the Sun. Like all other stars, the Sun generates its emitted energy in its central regions where densities and temperatures are high enough for nuclear fusion processes to take place. Because stellar cores are usually covered by an opaque envelope, most of our knowledge about them and their life-giving nuclear processes comes from theoretical modelling or from indirect observations such as the detection of solar neutrinos and the study of stellar pulsations, respectively. Only in very rare cases, stars may expose their cores, e.g., when a tiny fraction of them evolves into Wolf-Rayet or helium hot subdwarf stars. However, for the vast majority of stars, namely unevolved stars that burn hydrogen to helium in their centres, direct observational clues on the cores are still missing. Based on a comprehensive spectroscopic and asteroseismic analysis, we show here that the bright B-type star $γ$ Columbae is the stripped pulsating core (with a mass of $4$-$5\,M_\odot$, where $M_\odot$ is the mass of the Sun) of a previously much more massive star of roughly $12\,M_\odot$ that just finished central hydrogen fusion. The star's inferred parameters indicate that it is still in a short-lived post-stripping structural readjustment phase, making it an extremely rare object. The discovery of this unique star paves the way to obtain invaluable insights into the physics of both single and binary stars with respect to nuclear astrophysics and common-envelope evolution. In particular, it provides first observational constraints on the structure and evolution of stripped envelope stars.
