钡星系统轨道根数分布及丰度的Monte-Carlo模拟计算  

Monte Carlo Simulations on Orbital Elements and Abundance of Barium Stars

作　　者：石维彬[1] 牛萍[1] 张波[1] 刘俊红[2] 彭秋和[3] 

机构地区：[1]河北师范大学物理系,石家庄050016 [2]石家庄师范专科学校物理系,石家庄050041 [3]南京大学天文系,南京210093

出　　处：《天文学报》2003年第2期116-125,共10页Acta Astronomica Sinica

基　　金：国家自然科学基金(批准号:19973002)

摘　　要：采用星风质量吸积的角动量守恒模型,用Monte-Carlo方法研究了普通红巨星双星系统和钡星的轨道根数的变化规律。由于钡星系统是由普通红巨星双星系统演化而来,因此钡星系统的轨道偏心率及周期的分布显示了经过质量吸积后双星系统的最终轨道特征。计算结果表明,随着星风吸积过程的进行,在星风质量损失阶段系统轨道半长轴将增大,导致轨道周期增大,而偏心率变化不大,由此可以解释普通红巨星双星系统和钡星系统的轨道根数的分布规律和变化情况以及钡星重元素丰度分布特征。Carrying out a series of Monte-Carlo simulations, the changes of orbital elements of binaries are recalculated for wind accretion scenario of the total angular momentum conservation. As Ba star systems are evolved from G-K star systems, the distribution of orbital eccentricities and periods of Ba stars can show the final orbital character of binaries. Our results show that, during the evolution of a binary system, the system widens as it loses mass, and the orbital period increase, while orbital eccentricity remains nearly constant, which can explain the distribution regulation of orbital elements of normal G, K giant and barium stars and the distribution character of the heavy-element abundances of barium stars.

关 键 词：红巨星双星系统 钡星系统 质量吸积 星风吸积 外流 丰度 恒星 

分 类 号：P142.5[天文地球—天体物理]