Radial velocities of pulsating subdwarf B stars: KPD 2109+4401 and PB 8783
Radial velocities of pulsating subdwarf B stars: KPD 2109+4401 and PB 8783
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脉动亚矮星 B 星的径向速度：KPD 2109 4401 和 PB 8783
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
D. Pollacco
中科院分区：
文献类型：
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作者：
S. Jeffery;D. Pollacco
介绍了两颗脉动亚矮星B星KPD 2109 +4401和PB 8783的高速光谱学。径向运动被检测到与测光观测报告相同的频率，并在两个或多个独立的模式中具有-2kms 1的振幅。这些代表了第一次直接观测表面运动由于多模非径向振荡在亚矮星B星。在sdB+F双星PB 8783的情况下，两个分量的速度都被解析;高频振荡只在sdB星星中发现，而不是F星星。似乎也有证据表明，双组分的相互运动。如果得到证实，这意味着F型伴星的质量是sdB星星的1.2倍，而F星星在4小时内的加速度幅度将限制轨道周期在0.5到3.2 d之间。
High-speed spectroscopy of two pulsating subdwarf B stars, KPD2109+4401 and PB8783, is presented. Radial motions are detected with the same frequencies as reported from photometric observations and with amplitudes of � 2kms 1 in two or more independent modes. These represent the first direct observations of surface motion due to multimode non-radial oscillations in subdwarf B stars. In the case of the sdB+F binary PB8783, the velocities of both components are resolved; high-frequency oscillations are found only in the sdB star and not the F star. There also appears to be evidence for mutual motion of the binary components. If confirmed, it implies that the F-type companion is > � 1.2 times more massive than the sdB star, while the amplitude of the F star acceleration over 4 hours would constrain the orbital period to lie between 0.5 and 3.2d.