斜压转动恒星的引力昏暗效应研究

发布时间：2018-06-19 09:53

本文选题：Achernar + 演化　；参考：《贵州大学》2016年硕士论文

【摘要】：转动是影响恒星结构与演化中的重要因素之一。近年来大量的观测证实在恒星的自转作用下,恒星内部的物质将发生元素转移和角动量转移,从而在研究恒星结构和演化方面产生重要影响。观测表明Achernar是一颗接近于临界转动的恒星。本文根据Achernar的观测数据,用扰动理论推导了临界转动恒星Achernar分别作为单星和双星的斜压结构的特征,给出Achernar等压面上,压强,密度等物理量的分布,用考虑转动和潮汐效应的单、双星理论模型研究了它的引力昏暗现象。发现转动双星模型比单星模型更能符合Achernar的赤道和极半径之比的观测值。正剪切增大离心力,从而使赤道处的有效重力加速度和有效温度减小,反剪切则是增大离心力,对有效重力加速度和有效温度的作用正好相反。但是反剪切情况和刚性转动情况下的数值模拟结果,与Achernar的观测结果并不符。同样,可以看出初始转动角速度快的恒星比初始转动角速度慢的恒星,等价半径和中心密度在主序前,中期较大,而在主序后期较小。同时,由于初始转动角速度大的恒星,星风携带自转角动量损失多,造成后期演化角速度变小。另外,结果表明转动模型能增加恒星的中心集中度,而减少了恒星的四极矩,回旋半径,中心温度,氢燃烧产能率,转动恒星向赫罗图的低温和低光度演化。通过理论计算和观测对比发现,当Achernar自转角速度为151065.4--?s,正剪切率为0.7851时,Achernar极点处的有效温度和赤道处的有效温度分别为16041K、12073K。所有理论计算与观测值得相对误差不超过7%,是最好,最可能的理论模型。
[Abstract]:Rotation is one of the important factors that affect the structure and evolution of stars. In recent years, a large number of observations have proved that under the rotation of the stars, the material in the star will have element transfer and angular momentum transfer, which has an important influence on the study of the structure and evolution of stars. The observation shows that Achernar is a constant of the constant of the critical rotation. According to the observation data of Achernar, this paper derives the characteristics of the baroclinic structure of the critical rotating star Achernar as a single star and a binary star by the perturbation theory, gives the distribution of the physical quantities on the Achernar isobaric surface, pressure and density, and studies its gravitational dark phenomenon by the single and double Star theory model considering the rotation and tidal effects. The rotating double star model is more consistent with the observed value of the ratio of the equator to the polar radius of Achernar than the single star model. The positive shear increases the centrifugal force, thus reducing the effective gravity acceleration and effective temperature at the equator, and the reverse shear is the increase of the centrifugal force. The effect of the effective gravity acceleration and the effective temperature is the opposite. But the anti shear condition and the effect of the anti shear are the same. The results of numerical simulation in the case of rigid rotation do not correspond to the observation results of Achernar. Similarly, it can be seen that the star with a fast rotation angle is slower than the initial rotation angle. The equivalent radius and central density are before the main sequence, the middle period is larger, and the latter is smaller in the late main sequence. At the same time, star wind, due to the large initial rotation angle velocity, is the star wind. In addition, the results show that the rotational model can increase the central concentration of the star, and reduce the quadrupole moment, the radius of the rotation, the center temperature, the hydrogen burning productivity, the low temperature and low photometric evolution of the star to the herrograph. When the rotation speed of Achernar is 151065.4--? S and the positive shear rate is 0.7851, the effective temperature at the Achernar pole and the effective temperature at the equator are 16041K, and the relative error of all theoretical calculations and observations of 12073K. is not more than 7%, which is the best and most probable theoretical model.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P152

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