恒星在形成过程中释放的引力势能

Gravitational Potential Energy Releasing during the Star Formation

摘要: 在计算恒星的引力势能以及形成时标的时候，如果采用均匀球模型，会产生较大误差，因为恒星的密度从中心到表面差异非常大。我们采用Eggleton’s恒星演化程序构建了6种不同金属丰度、30种不同质量的零龄主序恒星模型。Eggleton’s恒星演化程序把恒星分成199个均匀同心壳层。我们推导出了恒星每个壳层的引力势能的精确表达式，精确地算出了恒星的引力势能；进而算出了恒星的引力势能系数和形成时标。我们算出的恒星引力势能系数和形成时标与前人的数据是一致的，我们的计算结果与年轻星团的观测图景也是相符合的。

Abstract: There is a great difference for stellar density from center to surface. If we think stellar density is homogeneous, it will get obvious error when we calculate stellar gravitational potential energy and star formation timescale. Using Eggleton’s code, we construct a series of zero age main sequence models of stars, with 6 metallicities and 30 masses. In Eggleton’s code, a star is divided into 199 homogeneous shells, with the same center. We get the accurate formula of gravitational potential energy for every shell, and calculate the potential energy for the whole star. Furthermore, we calculate the coefficient of stellar gravitational potential energy and star formation timescale. Our results are coincident with previous data and observation of young cluster.