Probing planet atmospheres and finding small planets nearby: paving the way for detecting life elsewhere

探测行星大气层并寻找附近的小行星：为探测其他地方的生命铺平道路

• 批准号: RGPIN-2018-05814
• 负责人: Lafrenière, David
• 金额: $ 7.29万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763424
• 关键词: Probing; planet; atmospheres; finding; small

Thousands of exoplanets have been discovered over the past two decades, enabling us to considerably expand our knowledge of their occurrence rate and bulk properties. The findings to date have triggered significant work to improve models of planet formation and evolution, and fuel our quest to find life elsewhere. The exoplanets caught in transit around bright stars allow us to peek through their atmosphere, and already we have detected a few molecules and placed loose constraints on the physical conditions in exoplanet atmospheres. However, the observations within our reach with current facilities face important limitations. Starting operation in late 2019, the James Webb Space Telescope (JWST) will completely revolutionize this field.I am a member of the instrument team of NIRISS, one of the four instruments of JWST, and using 200 hours of our guaranteed JWST observing time, I will lead a program to use NIRISS to acquire transit and eclipse spectroscopy observations of a sample of 16 exoplanets that span the full available range of equilibrium temperatures (300-3000 K) and masses (1 MEarth-10 MJup) for planets amenable to atmospheric characterization. Our observations will measure the abundance of the molecules and aerosols present in the exoplanets' atmosphere and determine their vertical and horizontal temperature structure with unprecedented precision. In turn this will allow us to address fundamental issues such as the formation process of planets and their subsequent evolution, the presence and characteristics of particulate clouds in planets' atmosphere, and non-equilibrium chemistry effects that might be at play in their atmosphere. Four of our targets are rocky and for these we intend to place some of the first constraints on the mean molecular weight and hence bulk composition of their atmosphere.I am also a member of the science teams of SPIRou and NIRPS, two new high-resolution, fiber-fed, near-infrared échelle spectrographs capable of precision radial velocity measurements. I will use these new powerful instruments to probe exoplanet atmospheres using the relatively new technique of high dispersion spectroscopy. These observations will be highly complementary to the lower resolution JWST observations, improving our determination of atmospheric composition and providing new information about the flow of gas in the planets' atmosphere. Using SPIRou and NIRPS, I will also participate in large radial velocity surveys to find new rocky planets around low-mass stars in the immediate neighborhood of the Sun. These surveys will uncover the best earth-like planets to search for biosignatures in the near-future, given their bright hosts and short orbital periods, and will provide a robust determination of the fraction of low-mass stars that host a habitable earth-like planet.

在过去的二十年中，已经发现了数千个系外行星，使我们能够考虑扩大我们对它们的发生率和批量特性的了解。迄今为止，这些发现引发了重要的工作，以改善行星形成和进化的模型，并促进我们寻求在其他地方找到生活的追求。围绕明亮恒星的过境捕获的系外行星使我们能够在它们的大气中窥视，并且我们已经检测到了一些分子，并在系超球层大气中的物理条件上放置了松散的约束。但是，我们目前设施的观察结果面临着重要的局限性。 Starting operation in late 2019, the James Webb Space Telescope (JWST) will completely revolutionize this field.I am a member of the instrument team of NIRISS, one of the four instruments of JWST, and using 200 hours of our guaranteed JWST observation time, I will lead a program to use NIRISS to acquire transit and eclipse spectroscopy observations of a sample of 16 exoplanets that span the full available range of equilibrium temperatures （300-3000 K）和质量（1 Mearth-10 MJUP），适用于大气表征的行星。我们的观察结果将测量外部大气层中存在的分子和气溶胶的丰度，并以前所未有的精度确定它们的垂直和水平温度结构。反过来，这将使我们能够解决基本问题，例如行星的形成过程及其随后的进化，行星大气中特定云的存在和特征以及可能在其大气中发挥作用的非平衡化学效应。我们的四个目标是岩石的，为此，我们打算对平均分子量的一些限制以及其大气的大量组成放置。我也是Spirou和Nirps科学团队的成员，这是两个新的高分辨率，纤维纤维，近交易，近交易的Echelle Echelle光谱仪，能够精确的radial radial velecity velecity velecity衡量。我将使用这些新的强大仪器使用高色散光谱的相对新技术来探测系外行星的大气。这些观察结果将高度互补，与较低的分辨率JWST观测值，改善了我们对大气组成的确定，并提供有关行星大气中气体流动的新信息。使用Spiou和Nirps，我还将参加大型径向速度调查，在太阳附近的低质量恒星周围找到新的岩石行星。这些调查将发现最佳的地球状行星，以在近乎燃烧的宿主和短轨道时期内寻找生物签名，并将为托有可居住的地球行星的低质量恒星提供强劲的确定。