转动潮汐变形双星理论模型研究  

Theoretical model of the rotationally and tidally distorted binaries

作　　者：詹琼[1] 宋汉峰[1,2,3] 邰丽婷 王江涛[1] 

机构地区：[1]贵州大学理学院物理系,贵阳550025 [2]中国科学院天体结构与演化重点实验室,昆明650011 [3]中科院国家天文台一贵州大学天文联合研究中心,贵阳550025

出　　处：《物理学报》2015年第8期412-421,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11463002);贵州省教育厅自然科学研究项目(批准号:黔教科2010002号);中国科学院天体结构与演化重点实验室开放课题(批准号:OP201107,OP201405);贵州大学自然科学青年基金(批准号:贵大自青基合字(2013)06号);贵州大学研究生创新基金(批准号:研理工2015055)资助的课题~~

摘　　要：转动和潮汐效应是影响双星系统结构和演化不可忽略的重要物理因素.根据大质量双星系统V478 Cyg的观测结果,检验了提出的转动潮汐变形的理论模型.将转动潮汐变形的模型与传统的双星演化模型对比发现:转动和潮汐效应使恒星外层(低于平均密度区)发生的形变远大于内层;恒星两极点重力加速度变大,赤道面上重力加速度变小;转动潮汐变形模型具有较大的半径、赤道速度和中心集中度,较低的氢核能产生率,恒星向低温和低光度端演化.此外,大质量双星系统V478 Cyg由潮汐形变造成的拱线运动速率大于转动形变造成的拱线运动速率,广义相对论效应造成的拱线运动最小.由于主星具有较高的中心集中度,次星潮汐、转动形变造成的拱线运动速率均大于主星相应的拱线运动速率.Rotation and tide are two important factors which have an influence on the stellar structure and evolution. They cannot be neglected. According to the observation data of the massive binary system V478 Cyg, we test the theoretical model including the deformation which is induced by rotation and tide （our model）. We compare our model with K^hler-Eggleton （KE） model, and the distorted model is more consistent with observations than the traditional model （KE model）. Besides, it is found that great deformation occurs in the outer envelope, where its density is lower than the mean density. Rotation and tide can cause the gravity at the two polar points to increase and the gravity in the equatorial plane to decrease. Therefore, the radiative flux, which depends on the local effective gravity, is not constant on the equipotentials any more. The poles which become hotter, experience a high mass loss than the equator, which becomes cooler. Furthermore, the two components in our model have bigger radii, equatorial velocities and central compactness and low H-energy production rate. The bigger mean radius of the distorted star produces a smaller temperature gradient inside the star, resulting in a lower energy transport. The lower energy generation rate inside the distorted model will widen the main sequence and increase the stellar lifetime. Stellar temperature and luminosity of the distorted model are shifted toward lower value. The tidal distortion inside the secondary star plays a most important role in the rate of the apsidal motion because of lower compactness. The apsidal motion derived from rotation is larger than the one derived from the general relativity.

关 键 词：恒星结构与演化 转动 潮汐 拱线运动 

分 类 号：P153[天文地球—天文学]