Understanding subdwarf B stars through asteroseismology

通过星震学了解亚矮星 B 星

• 批准号: 0307480
• 负责人: Michael Reed
• 金额: $ 29.15万
• 依托单位: Missouri State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307480&HistoricalAwards=false
• 关键词: Understanding; subdwarf; stars; through; asteroseismology

AST 0307480PI ReedAfter decades of progress in both stellar evolution theory and observational stellar astronomy, the late stages of evolution of most of the stars in our Galaxy - stages in which they shed their outer envelopes and expose their compact cores - conceal many still-unanswered questions. Recently, we have begun to exploit a powerful tool, astroseismology, for probing the interiors of stars and modeling their structure from oscillations and pulsations of the stars. Subdwarf B (sdB) stars are evolved stars located on the so-called horizontal branch of the Hertzsrung-Russell diagram, and they are thought to be the precursors of low mass white dwarf stars. Their progenitors are stars like our Sun. To date, the observational emphasis has been on discovering new pulsating sdB stars. With over 30 members discovered, the field is now mature enough to turn the success we have enjoyed applying astroseismology of white dwarfs to sdB stars. To do so requires that sufficient photometric data be obtained to resolve the often complex pulsation structure of individual objects. As horizontal branch stars, sdB stars are burning helium in their cores, With their limited hydrogen envelopes, these stars have no shell hydrogen burning simplifying their structure, and making them easier to model. Thus far only a few pulsating sdB stars have resolved pulsation spectra, some of which have revealed very interesting results. The goal of this research is to fully apply the tools of astroseismology to sdB stars by resolving the pulsation spectra of several additional members. This requires substantial telescope time to be split between national facilities, Baker Observatory (operated by our home institution), and multi-site observational campaigns with international collaborators. Pulsating stars may also be used to look for planets. Companions to sdB stars can be detected as periodic variations in the pulsation phases. Such measurements are readily sensitive to sub-Jupiter mass planets with long periods. Broader impacts. Undergraduate students will assist in obtaining and reducing the data in this research project. By exposing undergraduate students to research, they are better able to decide if astronomy is the correct career path for them. Additionally, it allows Southwest Missouri State's students to competitively apply for graduate programs based on a strong undergraduate research experience.

AST 0307480PI REEDAFTER数十年来恒星进化论和观察性恒星天文学的进步，这是我们银河系中大多数恒星进化的后期 - 他们摆脱了外部信封并暴露了紧凑的核心 - 隐藏了许多仍然无固定的问题。最近，我们已经开始利用一种强大的工具，即Arstoseology，用于探测恒星的内部并从恒星的振荡和脉动中对结构进行建模。 Subdwarf B（SDB）恒星是位于赫尔茨隆 - 鲁塞尔图的所谓水平分支上的恒星，被认为是低质量白矮星恒星的前体。他们的祖细胞是像我们的太阳一样的明星。迄今为止，观察重点一直在发现新的脉动SDB星。有30多名成员发现，该领域现在已经足够成熟，可以使我们喜欢将白矮星的星星学学在SDB明星上应用。为此，需要获得足够的光度数据来解决单个对象的通常复杂的脉动结构。作为水平分支星星，SDB恒星在其内核中燃烧氦气，并且氢信封有限，这些恒星没有壳氢燃烧简化其结构，并使其易于建模。 迄今为止，只有少数脉动的SDB星已经解析了脉动光谱，其中一些揭示了非常有趣的结果。这项研究的目的是通过解决其他几个成员的脉动光谱来充分应用星际学的工具。这需要大量的望远镜时间在国家设施，贝克天文台（由我们的家庭机构运营）和与国际合作者进行多站点的观察活动之间分配。脉动恒星也可以用于寻找行星。可以将SDB恒星的同伴视为脉动阶段的周期性变化。此类测量很容易对长时间的亚jupiter质量行星敏感。更广泛的影响。 本科生将协助获得和减少该研究项目中的数据。通过使本科生进行研究，他们可以更好地确定天文学是否是他们的职业道路。此外，它允许西南密苏里州立大学的学生根据强大的本科研究经验竞争性地申请研究生课程。