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- 2016
转动恒星引力昏暗效应及演化研究
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Abstract:
摘要： 转动和潮汐效应是影响恒星结构和演化非常重要的物理因素。根据Achernar的观测数据,用考虑转动和潮汐效应的单、双星模型,研究了Achernar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观测值。计算结果表明,初始转动角速度快的恒星,其等价半径和中心密度在主序阶段的开始至40 Myr较大,随后变小。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,转动效应能增加恒星的中心集中度,但减少恒星的四极矩、回旋半径、中心温度、氢燃烧产能率,使转动恒星向赫罗图的低温和低光度演化。
Abstract: Rotation and tide are two important factors which have very important impact on the stellar structure and evolution. Based on the observational data of Achernar, we have investigated the gravitational darkening with the models including the effects of rotation and tide. We find that the rotating binaries can be more consistent with the observations of the ratio of equatorial radius to the polar one than the single rotating model. It is shown that the star with the initial larger angular velocity has bigger radius and central density at the beginning and middle of the main sequence, and it has smaller radius and central density due to the large loss of spin angular momentum in subsequent evolution. Also, we have found that rotation can make the star more centrally condensed and enlarged in size, decreasing the quadrupolar momentum, the gyration radius, central temperature, and the rate of the hydrogen production energy in the stellar core. The star shifts towards low temperature and luminosity in the HR diagram in rotating model
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