论文标题
关于降低风质量速率在使外球星形塑造行星星云中的作用
On the role of reduced wind mass-loss rate in enabling exoplanets to shape planetary nebulae
论文作者
论文摘要
我们使用恒星进化代码梅萨二元，并遵循三个系外行星和两个棕色矮人（BDS）的进化来确定它们在其母星在其未来的红色巨型分支（RGB）和渐近巨型分支（AGB）上的潜在作用。我们将这项研究限制为具有半轴轴为1AU <a0 <20AU的轨道的系外行星和BD，高偏心率，E0> 0.25，并且具有质量m> 1mo的母星。我们发现，在RGB阶段，Star Hip 75458将吞噬其髋关节75458 B的行星。行星将去除信封并终止RGB的演化，留下质量为0.4mo的裸露氦芯，该氦气将进化为形成氦白矮人。只有在五个系统中，beta beta pic c C将在AGB阶段进入其母星的信封。为此，我们必须将风质量减少率从其常用值中降低了约四倍。这加强了一个早期结论，该结论基于具有圆形轨道的系外行星，指出具有不可忽略的AGB恒星的分数，我们应该考虑较低的隔离AGB恒星的风质量降低速率（在由同伴旋转之前）。这种吞噬的行星可能导致AGB质量减少几何形状形成椭圆形的星云。
We use the stellar evolution code MESA-binary and follow the evolution of three exoplanets and two brown dwarfs (BDs) to determine their potential role in the future evolution of their parent star on the red giant branch (RGB) and on the asymptotic giant branch (AGB). We limit this study to exoplanets and BDs with orbits that have semi-major axis of 1AU<a0<20AU, a high eccentricity, e0>0.25, and having a parent star of mass M>1Mo. We find that the star HIP 75458 will engulf its planet HIP 75458 b during its RGB phase. The planet will remove the envelope and terminate the RGB evolution, leaving a bare helium core of mass 0.4Mo that will evolve to form a helium white dwarf. Only in one system out of five, the planet beta Pic c will enter the envelope of its parent star during the AGB phase. For that to occur, we have to reduce the wind mass-loss rate by a factor of about four from its commonly used value. This strengthens an early conclusion, which was based on exoplanets with circular orbits, that states that to have a non-negligible fraction of AGB stars that engulf planets we should consider lower wind mass-loss rates of isolated AGB stars (before they are spun-up by a companion). Such an engulfed planet might lead to the shaping of the AGB mass-loss geometry to form an elliptical planetary nebula.
