Energetic radiation from exoplanet hosts: The most detailed study of our nearest host star Proxima Centauri

来自系外行星宿主的高能辐射：对我们最近的宿主恒星比邻星的最详细研究

• 批准号: 361764860
• 负责人: Dr. Christian Schneider
• 金额: --
• 依托单位: Hamburger Sternwarte
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/361764860?language=en
• 关键词: Energetic; radiation; exoplanet; hosts; most

Proxima Cen b is the nearest exoplanet to Earth - and possibly habitable. The latter, however, depends critically on the illumination by high-energy radiation from its host star, which is an active M dwarf. No models exist that allow a sufficiently accurate prediction of the stellar high-energy spectrum to answer the question of habitability without detailed observations in the X-ray and UV regimes.We have organized the so far most extensive X-ray to UV observing campaign of Proxima Cen to simultaneously measure the complete high-energy spectrum with unprecedented detail. This includes a massive 175 ks of Chandra X-ray coverage using the Low Energy Transmission Grating Spectrometer covering wavelengths from about 2 - 175 A, accompanied by five simultaneous orbits of Hubble Space Telescope UV data as well as coverage at higher energies with the ASTROSAT satellite, plus supporting ground-based data. The goals of this project are twofold: First, we will create broad-band spectral energy distributions for different activity levels of Proxima Cen to enable a detailed assessment of the habitability of our nearest exoplanetary neighbor and, second, to use the proximity of the target to advance our understanding of magnetic activity on low-mass stars, which likely outnumber other types of planet hosts in our Galaxy. Hence, to better understand the astrophysical conditions necessary to harbor life and how common these are in our Milky Way, i.e., directly addresses the one of the main questions posed in the announcement of the Priority Programme "Exploring the Diversity of Extrasolar Planets" (SPP 1992).

比邻星b是距离地球最近的系外行星--而且可能适合人类居住。然而，后者严重依赖于其主星的高能辐射的照明，而主星是一颗活跃的M矮星。在没有详细的X射线和紫外线观测的情况下，没有模型可以足够准确地预测恒星高能谱来回答宜居性问题。我们组织了比邻星迄今为止最广泛的X射线到紫外线观测活动，以前所未有的细节同时测量完整的高能谱。这包括使用低能量传输光栅光谱仪覆盖约2-175A的波长范围的175K巨大的钱德拉X射线覆盖范围，伴随着五个同步轨道的哈勃空间望远镜紫外线数据，以及ASTROSAT卫星在更高能量下的覆盖范围，加上辅助的地面数据。这个项目的目标有两个：首先，我们将为比邻星的不同活动水平创建宽带光谱能量分布，以便能够详细评估我们最近的系外行星邻居的宜居性；其次，利用目标的接近程度来促进我们对低质量恒星上的磁活动的理解，低质量恒星的数量可能超过我们银河系中其他类型的行星宿主。因此，为了更好地了解孕育生命所必需的天体物理条件以及这些条件在我们银河系中的普遍程度，即直接解决优先方案“探索太阳系外行星多样性”(SPP 1992)中提出的主要问题之一。