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.

我的研究主要旨在通过分析在恒星内部反弹的声波的谐波结构来了解恒星的工作原理。声波不是被听到的，而是被看到的。当声波穿过恒星内部时，它会导致恒星的物质上下振荡，进入恒星较温暖和较冷的区域。在恒星表面，材料温度的变化可以被视为恒星亮度的微小变化。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正在发生的情况的图像。我们的方法在很多方面类似于地震学家利用地震产生的振动绘制地球内部组成的技术。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周，不受天气和日光的干扰。此外，我们还需要避免地球大气层的闪烁效应。因此，我们必须使用专门设计、专门用于观察光线微小变化的“太空望远镜”进行观察。加拿大科学家是第一个建造并发射此类卫星的人。这颗名为 MOST（恒星微变率和振荡）的卫星现已运行三年多。我和我的研究同事一直在分析从卫星获得的数据，以构建类太阳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。前主序恒星是年轻的恒星，最近形成，仍在塌缩，尚未燃烧核燃料。巨星是膨胀的恒星，接近生命的终点。我和其他星震学家（我们现在这样称呼自己）希望建立一个关于像太阳这样的恒星的诞生、生命和死亡的严格模型。