Finding a second Earth through stellar understanding

通过对恒星的了解寻找第二个地球

• 批准号: MR/X033244/1
• 负责人: Annelies Mortier
• 金额: $ 163.91万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FX033244%2F1
• 关键词: Finding; second; Earth; through; stellar

People, including me, have wondered for centuries if we are alone in the Universe. Only a mere thirty years ago, the first planet orbiting a star other than the Sun was discovered. These newly discovered worlds were called exoplanets. Over the last three decades we have witnessed an exponential rise in the number of known exoplanets, with more than 5000 discovered so far. This has shown that exoplanets are ubiquitous and come in various sizes and architectures. At the same time, a planet truly resembling Earth or a planetary system resembling the Solar System, has not yet been discovered.My project will for the first time enable to find a planet resembling Earth orbiting a star resembling the Sun. Exoplanets can be detected by observing and modelling the gravitational wobble of their hosting star, seen in their changing radial velocities over time. Furthermore, the technique of using radial velocity changes is currently the only viable way of measuring the mass of small exoplanets. Unfortunately, for small long-period exoplanets such as Earth, these velocity changes are well below the stellar-induced changes in the radial velocity. These stellar signals are due to the surface variability of the stellar magnetic field and thus drown out the smaller signals from far-away exoplanets.I will improve our ability to measure and extract the tiny signals of small exoplanets. This will be done by accounting for the stellar magnetic field variability in the spectroscopic data. I will use our brightest known star, the Sun, as a teststar to develop new techniques to deal with the stellar data. Removing the effect of the known planets in the Solar System, the Sun can act as the only known star where we are certain there are no planetary signals in the data. This creates a unique opportunity to test and improve new techniques before using them on other stars.As a Future Leader Fellow, I will expand our instrumental capacities to study the Sun-as-a-star and characterise the small exoplanets found around other stars. As part of the project, I will build and exploit a new Solar Telescope to measure both stable radial velocities and the simultaneous changes in the Solar magnetic field. This unique instrument would be the first of its kind to have polarimetric capabilities that will open the pathway to discovering smaller and more distant exoplanets.To place Earth and the Solar System into the context of the full exoplanet population, I will study the connection between stellar and planetary composition. I can do this using the same spectroscopic data used already in my project to find and characterise the exoplanets. By accurately characterising exoplanet systems as a whole, we will gain insight into the specific details of planet formation and evolution and the possibilities for existence of life on other planets. This will bring us one step closer to understanding our place in the Universe and how unique Earth could be.

包括我在内的人们已经想知道几个世纪以来我们是否独自一人在宇宙中。仅仅三十年前，就发现了第一个绕太阳以外的恒星行驶的行星。这些新发现的世界被称为系外行星。在过去的三十年中，我们目睹了已知系外行星的数量呈指数增长，到目前为止发现了5000多个。这表明系外行星无处不在，有各种尺寸和体系结构。同时，尚未发现一个类似于地球或类似太阳系的行星系统的行星。可以通过观察和建模其宿主恒星的重力摇摆来检测外球星星，这些恒星随着时间的流逝而变化的径向速度在变化中。此外，使用径向速度变化的技术目前是测量小型系外行星质量的唯一可行方法。不幸的是，对于小的长期外行系外行星，例如地球，这些速度变化远低于径向速度恒星引起的变化。这些恒星信号是由于恒星磁场的表面变异性引起的，因此淹没了远距离外球星的较小信号。我将提高我们测量和提取小型系外行星的微小信号的能力。这将通过考虑光谱数据中出色的磁场变异性来完成。我将使用我们最亮的恒星The Sun作为测试明星，以开发新技术来处理出色的数据。删除已知行星在太阳系中的效果，太阳可以充当我们确定数据中没有行星信号的唯一已知恒星。这为在其他恒星上使用之前，创造了一个独特的机会来测试和改进新技术。作为未来的领导者，我将扩大我们的乐器能力来研究Sun-As-A-A-Star，并描述其他恒星周围发现的小型系外行星。作为项目的一部分，我将构建和利用新的太阳能望远镜，以测量稳定的径向速度和太阳能磁场的同时变化。这种独特的乐器将是同类产品中的第一个具有偏振能力的功能，该功能将为发现较小，更遥远的系外行星开辟途径，将地球和太阳系置于完整的系外行星种群的背景下，我将研究恒星之间的联系和行星构成。我可以使用项目中使用的相同光谱数据来查找和表征系外行星。通过准确表征整个系外行星系统，我们将深入了解行星形成和进化的特定细节以及其他行星上生命存在的可能性。这将使我们更加了解我们在宇宙中的地位以及地球的独特之处。