Stellar Seismology

恒星地震学

• 批准号: 155320-2007
• 负责人: Guenther, David
• 金额: $ 3.38万
• 依托单位: Saint Mary's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=363441
• 关键词: Stellar; Seismology

My research is primarily directed toward understanding how stars work by analyzing the harmonic structure of sound waves that bounce around their interiors. The sound waves are not heard but seen. As a sound wave travels through the interior of a star it causes the material of the star to oscillate up and down into warmer and cooler regions of the star. The changes in temperature of the material can be seen on the surface of a star as minute variations in the star's brightness. From the brightness fluctuations, we can deduce the frequency and amplitude of the sound waves, which, in turn, can be used to build a picture of what is going on inside the star. Our methods are in many ways similar to the techniques used by seismologists to map out the composition of the interior of the earth using the vibrations produced by earthquakes.In order to clearly see the fluctuations we need to observe the same star continuously for at least a couple of weeks, without interruption from weather and daylight. In addition, we need to avoid the twinkling effects of the earth's atmosphere. Therefore, we must observe from a "space telescope" specifically designed and dedicated to observing the tiny variations in light. Canadian scientists were the first to build and launch such a satellite. The satellite, called MOST (Microvariability and Oscillations on STars), has been in operation now for over three years. My research colleagues and I have been analyzing the data obtained from the satellite to build a detailed picture of the interiors of sun-like stars.I will soon direct my attention to pre-main-sequence and giant stars. Pre-main-sequence stars are young stars, recently formed, still collapsing, and not yet burning nuclear fuel. Giant stars are swollen stars, near the end of their life. I along with other asteroseismologists (as we have come to call ourselves) hope to build a well constrained model of the birth, life, and death of stars like our sun.

我的研究主要是通过分析在恒星内部反弹的声波的谐波结构来了解恒星是如何工作的。声波是看不见而听不见的。当声波穿过恒星内部时，它会导致恒星的物质上下振荡，进入恒星的温暖和寒冷的区域。物质温度的变化可以通过恒星亮度的微小变化在恒星表面被观察到。从亮度波动中，我们可以推断出声波的频率和振幅，进而可以用来构建恒星内部情况的图像。我们的方法在许多方面与地震学家利用地震产生的振动来绘制地球内部成分图的技术相似。为了清楚地看到波动，我们需要连续观察同一颗恒星至少几个星期，不受天气和日光的干扰。此外，我们需要避免地球大气层的闪烁效应。因此，我们必须通过专门设计的“太空望远镜”来观察光线的微小变化。加拿大科学家是第一个建造并发射这种卫星的人。这颗卫星被称为MOST（恒星的微变异和振荡），已经运行了三年多。我和我的研究同事一直在分析从卫星上获得的数据，以建立一个类似太阳的恒星内部的详细图像。我很快就会把注意力转向前主序星和巨星。前主序星是年轻的恒星，刚刚形成，还在坍塌，还没有燃烧核燃料。巨星是膨胀的恒星，接近生命的尽头。我和其他星震学家（我们已经这样称呼自己了）希望建立一个很好的约束模型，来描述像太阳这样的恒星的诞生、生命和死亡。