Cloudbusting with JWST: characterising aerosols, aurorae and chemistry in substellar atmospheresto the water cloud regime

使用 JWST 进行云消除：描述水云状态下恒星大气中的气溶胶、极光和化学成分

• 批准号: ST/X001091/1
• 负责人: Ben Burningham
• 金额: $ 41.37万
• 依托单位: University of Hertfordshire
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FX001091%2F1
• 关键词: Cloudbusting; JWST; characterising; aerosols; aurorae

JWST will revolutionise the study of alien worlds via its sensitivity to the wavelengths where most of their heat escapes into space - wavelengths of light that cannot be observed easily from the ground. One of the most important groups of planets that JWST will target are giant planets, similar to Jupiter, that orbit other stars. These worlds are important for understanding how planetary systems form and evolve because they represent most of the mass in their planetary systems, in the same way that Jupiter dominates our own Solar system. And, like Jupiter, giant exoplanets are thought to play an important role in delivering water to rocky, possibly habitable, planets in their systems. Giant planets are also the easiest planets to observe outside the Solar System, so they also provide a testing ground for enhancing our ability to study all kinds of exoplanets, even potentially habitable ones. One of the most challenging problems in studying exoplanets is how to deal with clouds. Clouds block our view, and also change the composition and other properties of alien atmospheres in complicated and difficult to measure ways. Because of this, clouds are often seen as an obstacle to exoplanet science. However, thanks to JWST and the analysis tools that we have developed, clouds will soon be able provide new insights into the composition, chemistry and dynamics of alien worlds. Alongside clouds, powerful aurorae have been discovered on free floating Jupiter-like worlds known as brown dwarfs, and we expect to find similar aurorae on giant exoplanets in the future. Interestingly, all the brown dwarfs that show aurorae also show variations in their brightness as they rotate. Such variability has been seen in many other brown dwarfs and even some giant exoplanets, and it is generally thought to be due to weather creating bright and dark patches due to differing cloud cover. It is also possible that some of the variability is driven by aurorae, or even that weather, and associated large scale atmospheric flows, may interact with the aurorae in ways yet to be discovered. With this funding, we will learn how to decode JWST spectra of distant worlds to reveal their cloud properties, composition, and thermal structure, and understand how their aurorae interact with their atmospheres. We will also use JWST to study some of the coolest brown dwarfs known, called Y dwarfs. Y dwarfs are cool enough to have water ice clouds in their atmospheres. These will be the first studies of water clouds beyond the Solar system. Thanks to prior knowledge of the compositions of some of these brown dwarfs, we will be able to calibrate our understanding of clouds, and then use this knowledge to study giant planets. We will also be able to test different theories of cloud formation and chemistry, as well as study the weather on these alien worlds. This work will develop techniques that we will need in order study all kinds of cloudy exoplanets. It will also pave the way for robust estimates of the composition of giant exoplanets - an essential piece of evidence for revealing their formation histories and that of their home planetary systems.

JWST将通过对波长的敏感性来彻底改变对外星世界的研究，在该波长中，大部分热量逸出到太空中 - 光波长无法轻易从地面观察到。 JWST目标的最重要的行星之一是巨型行星，类似于木星，它绕了其他恒星。这些世界对于理解行星系统如何形成和发展很重要，因为它们代表了行星系统中的大部分质量，就像木星主导着我们自己的太阳系一样。而且，像木星一样，巨型系外行星被认为在其系统中向岩石（可能可居住的行星）运送水方面起着重要作用。巨型行星也是在太阳系之外观察的最简单的行星，因此它们还提供了一个测试场，以增强我们研究各种系外行星，甚至潜在可居住的能力。研究系外行星最具挑战性的问题之一是如何处理云。云阻止了我们的观点，还以复杂且难以衡量的方式改变了外星气氛的组成和其他特性。因此，云通常被视为系外行星科学的障碍。但是，多亏了JWST和我们开发的分析工具，云将很快能够对外星世界的组成，化学和动态提供新的见解。除了云层，在自由浮动的木星般的世界上发现了强大的极光，我们希望将来会在巨型系外行星上找到类似的Aurorae。有趣的是，所有显示Aurorae的棕色矮人在旋转时也会显示出亮度的变化。在许多其他棕色矮人，甚至一些巨大的系外行星中都可以看到这种可变性，通常认为这是由于天气造成的，由于云覆盖率不同而造成了明亮和黑暗的斑点。某些可变性也可能是由极光驱动的，甚至是天气以及相关的大规模大气流，可能会以尚未发现的方式与Aurorae相互作用。通过这笔资金，我们将学习如何解码遥远世界的JWST光谱以揭示其云特性，成分和热结构，并了解其极光如何与大气相互作用。我们还将使用JWST研究一些名为Y Dwarfs的最酷的棕色矮人。 y矮人足够凉爽，可以在其大气中放水。这些将是对太阳系以外的水云的第一批研究。得益于对这些棕色矮人中一些矮人的组成的先验知识，我们将能够校准我们对云的理解，然后使用这些知识来研究巨型行星。我们还将能够测试云形成和化学的不同理论，并研究这些外星世界的天气。这项工作将开发我们将需要的技术，以便研究各种多云的系外行星。这也将为巨大系外行星组成的强大估计铺平道路，这是揭示其形成历史和家居行星系统的重要证据。

项目成果

Predicting Cloud Conditions in Substellar Mass Objects Using Ultracool Dwarf Companions

使用超冷矮星伴星预测亚恒星质量天体中的云状况

• DOI: 10.3847/1538-4357/ad1f6d
• 发表时间: 2024
• 期刊: The Astrophysical Journal
• 作者: Calamari E