Orbital Period Changes and Possible Mass and Angular Momentum Loss in Two Algol-Type Binaries: RW Coronae Borealis and TU Herculis
Orbital Period Changes and Possible Mass and Angular Momentum Loss in Two Algol-Type Binaries: RW Coronae Borealis and TU Herculis
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DOI：
10.1086/301217
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发表时间：
2000-02
期刊：
影响因子：
--
通讯作者：
Q. Shengbang
中科院分区：
文献类型：
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作者：
Q. Shengbang
本文研究了两个大陵型双星RW CrB和TU Her的轨道周期。发现RW CrB的轨道周期以dP/dt = -4.29 × 10 ~（-8）days yr ~（-1）的速率长期减小，而TU Her的轨道周期则以复杂的方式变化。轨道周期以dP/dt = -2.92 × 10- 6dyr-1的速率长期递减，并出现两次跳跃。对其它Algol型双星的轨道周期下降率dP/dt进行了修正，并讨论了轨道周期P与轨道周期变化率dP/dt之间的统计关系。这些系统的轨道周期变化的性质，结合它们的半独立结构，表明它们在演化过程中可能经历长期质量和角动量损失（AML）。叠加在轨道周期长期下降上的不规则突变可能是由传质和AML过程中的某些不稳定性引起的。
The orbital period of two Algol-type binaries, RW CrB and TU Her, are studied. It is discovered that the orbital period of RW CrB shows a secular decrease at the rate of dP/dt = -4.29 × 10-8 days yr-1, while the orbital period of TU Her varies in some complex way. Two jumps in the orbital period are found while it undergoes secular decrease at a rate of dP/dt = -2.92 × 10-6 days yr-1. The rates of decrease of the orbital periods dP/dt in other Algol-type binaries are revised and the statistical relation between the orbital period P and its rate of change dP/dt is also discussed. The properties of the changes in the orbital period of these systems, combined with their semidetached configurations, demonstrate that they may be undergoing secular mass and angular momentum loss (AML) during their evolution. The irregular abrupt changes that are superposed on the secular decrease of the orbital period may be caused by some instabilities during the mass transfer and AML.