Abstract

In this paper, the orbital evolution of exoplanets at the late stages of stellar evolution was studied using the population synthesis method. Stellar evolution was traced from the main sequence stage to the white dwarf stage. The evolutionary tracks were calculated using the MESA package. The statistics of planets that were absorbed, ejected from the system, and surviving by the time of the transformation of parent stars into white dwarfs was calculated considering the variation in the star formation rate over the entire lifetime of the Galaxy. We considered planets around stars in the range of initial masses (1–8)\({{M}_{ \odot }}\) since less massive stars do not leave the main sequence over the lifetime of the Galaxy, and more massive stars do not lead to the formation of white dwarfs. It was found that for the adopted initial distributions of planets on the a–M_pl plane, the majority (about 60%) of planets born around stars in the mass range under study are absorbed by parent stars at the giant stage. A small fraction of planets (less than a percent) are ejected out of their systems under the action of the stream of matter escaping the star. The estimated number of “runaway” planets with masses from 0.04 Earth masses to 13 Jupiter masses in the Galaxy is approximately in the 300 million range.

中文翻译：

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系恒星演化引起的轨道变化的系外行星总数

摘要

本文使用种群合成方法研究了恒星演化后期系外行星的轨道演化。从主序阶段到白矮星阶段可以追溯到恒星的演化。进化轨迹是使用MESA软件包计算的。考虑到恒星形成率在银河系整个生命周期中的变化，计算出了被吸收，从系统中弹出，并在母恒星转化为白矮星时幸存的行星的统计数据。我们考虑了初始质量（1–8）\（{{M} _ {\ odot}} \）范围内围绕恒星的行星因为质量较小的恒星在银河系的整个生命周期中不会离开主要序列，质量较大的恒星不会导致白矮星的形成。研究发现，对于在a - M _pl平面上采用的行星初始分布，研究质量范围内恒星周围出生的大多数行星（约60％）在巨型阶段被母恒星吸收。在逃逸恒星的物质流的作用下，一小部分行星（不到百分之一）从其系统中弹出。星系中质量从0.04地球质量到13木星质量的“失控”行星的估计数量大约在3亿个范围内。