Sounding the Stars - Asteroseismology of Stars with Sun-like Oscillations

探寻星星——具有类太阳振荡的恒星的星震学

• 批准号: ST/F002041/1
• 负责人: William Chaplin
• 金额: $ 42.75万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FF002041%2F1
• 关键词: Sounding; Stars; Asteroseismology; Sun; like

Stars are building blocks of the universe, and are crucial sources of energy for giving conditions which can support life. Knowledge on how stars are born, live, evolve, and then die, underpins much of our understanding of the universe. Our research will 'peer' deep inside stars to understand how they work, and to add previously unknown knowledge on the life-cycles of the stars. Our research will also provide important information for 'planet hunters', who are searching for potentially habitable planets like Earth orbiting other stars. We are interested in stars that vibrate gently like our own star, the Sun. Although you cannot see it without special equipment, the Sun is shaking. Bubbling motion just under the visible surface of the Sun is constantly feeding in energy, and the Sun responds by vibrating just like a (very) large musical instrument. The 'notes' of the Sun's music are very interesting to astronomers. They are made by sound waves, some of which have travelled deep inside the Sun, and their frequencies (the pitch of the notes) depend on conditions they meet on the way. For example, the frequencies depend on the density and temperature of the material inside the Sun, and studying them allows astronomers to essentially get an ultrasound scan of our nearest star by 'sounding' its interior. Because the Sun is a ball of largely ionized gas, when it shakes it gently oscillates. The oscillations make the surface move to and fro at a couple of metres per second (a slow walking pace!), and it takes about 5 minutes to go through a complete cycle. Just detecting this small movement is very hard, and takes specially designed instruments. But doing so for other stars is much, much harder again, because they are many orders of magnitude fainter than the Sun. The solar oscillations were discovered in the 1960s, and it took until the mid to late 1990s for ingenious astronomers to discover oscillations like them on another star. There are now more than a dozen stars that have been observed to oscillate like the Sun. They range from stars that both look like, and are at the same points in their life cycles, as the Sun; through to much more mature stars that have expanded in their old ages to become 'red giants'. We now stand on the threshold of an exciting expansion in observations of the oscillations on other stars, with the launch of new space missions, and continuation of observations from telescopes around the world. These observations will allow astronomers to test their theories of how all stars live and evolve, by peering into their interiors, like we can for the Sun. That is what we propose to do. We will use the exciting new data from telescopes and space missions to 'sound the stars'. Our work will also go hand-in-hand with searches for Earth-like planets around other stars. That is because we will use data from NASA's Kepler space mission, which will look for oscillations and hunt for planets, at the same time. Our work will help to reveal the nature of stars around which planets are found, and will also give us more information on the planets themselves.

恒星是宇宙的基石，也是维持生命的重要能量来源。关于恒星如何诞生、生存、进化和死亡的知识，是我们对宇宙理解的基础。我们的研究将深入恒星内部，了解它们是如何工作的，并增加以前未知的恒星生命周期知识。我们的研究还将为“行星猎人”提供重要信息，他们正在寻找像地球这样绕其他恒星运行的潜在宜居行星。我们对像我们的星星--太阳--一样轻轻振动的恒星感兴趣。虽然没有特殊的设备你看不到它，但太阳正在摇晃。太阳可见表面下的气泡运动不断提供能量，太阳通过振动做出反应，就像一件（非常）大的乐器一样。太阳音乐的“音符”对天文学家来说非常有趣。它们是由声波产生的，其中一些已经深入太阳内部，它们的频率（音符的音高）取决于它们在途中遇到的条件。例如，频率取决于太阳内部物质的密度和温度，研究它们可以让天文学家通过“探测”其内部来获得离我们最近的星星的超声扫描。因为太阳是一个大部分电离气体的球，当它震动时，它会轻轻地振荡。这种振荡使表面以每秒几米的速度来回移动（一个缓慢的步行速度！），一个完整的循环大约需要5分钟。光是检测这种微小的运动就非常困难，需要专门设计的仪器。但是对其他恒星这样做又困难得多，因为它们比太阳暗许多数量级。太阳振荡是在20世纪60年代被发现的，直到20世纪90年代中后期，天才的天文学家才在另一颗星星上发现了类似的振荡。现在有十几颗恒星被观察到像太阳一样振荡。它们的范围从看起来像太阳的恒星，到在生命周期中处于相同点的恒星;到更成熟的恒星，它们在年老时膨胀成为“红巨星”。我们现在站在一个令人兴奋的扩展在其他恒星上的振荡观测的门槛上，随着新的太空任务的启动，以及世界各地望远镜观测的继续。这些观测将使天文学家能够测试他们关于所有恒星如何生活和进化的理论，通过观察它们的内部，就像我们对太阳一样。这就是我们建议要做的。我们将使用来自望远镜和太空任务的令人兴奋的新数据来“探测恒星”。我们的工作还将与其他恒星周围的类地行星搜索密切相关。这是因为我们将使用来自美国宇航局开普勒太空使命的数据，该任务将同时寻找振荡和行星。我们的工作将有助于揭示发现行星的恒星的性质，也将为我们提供更多关于行星本身的信息。

项目成果

Determining stellar radii using large separations: an error analysis

• DOI: 10.1007/s10509-009-0164-x
• 发表时间: 2010-07
• 期刊: Astrophysics and Space Science
• 影响因子: 1.9
• 作者: S. Basu;W. Chaplin;Y. Elsworth

Solar-like oscillations in HD 181420: data analysis of 156 days of CoRoT data

HD 181420中的类太阳振荡：156天CoRoT数据的数据分析

• DOI: 10.1051/0004-6361/200911937
• 发表时间: 2009
• 期刊: Astronomy & Astrophysics
• 影响因子: 6.5
• 作者: Barban C

SOLAR-LIKE OSCILLATIONS IN LOW-LUMINOSITY RED GIANTS: FIRST RESULTS FROM KEPLER

低光度红巨星中的类太阳振荡：开普勒的第一个结果

• DOI: 10.1088/2041-8205/713/2/l176
• 发表时间: 2010
• 期刊: The Astrophysical Journal
• 作者: Bedding T

DETERMINATION OF STELLAR RADII FROM ASTEROSEISMIC DATA

• DOI: 10.1088/0004-637x/710/2/1596
• 发表时间: 2009-09
• 期刊: The Astrophysical Journal
• 作者: S. Basu;W. Chaplin;Y. Elsworth

A MULTI-SITE CAMPAIGN TO MEASURE SOLAR-LIKE OSCILLATIONS IN PROCYON. II. MODE FREQUENCIES

测量南河三星中类太阳振荡的多站点活动。

• DOI: 10.1088/0004-637x/713/2/935
• 发表时间: 2010
• 期刊: The Astrophysical Journal
• 作者: Bedding T