标题： TNG的GAPS项目。 LXI。 TESS年轻系外行星宿主恒星的大气参数和元素丰度 显示英文标题

标题： The GAPS Programme at TNG. LXI. Atmospheric parameters and elemental abundances of TESS young exoplanet host stars

摘要： 研究处于不同演化阶段的系外行星有助于了解它们的形成、迁移和演化。 确定系外行星的属性依赖于其宿主恒星的属性。 因此，对宿主恒星进行表征以获得关于行星的准确知识非常重要。 我们的最终目标是以一致且精确的方式推导出GAPS计划中使用TNG光谱仪上的HARPS-N仪器跟踪的十颗年轻TESS凌日系外行星宿主GK恒星的恒星大气参数和元素丰度。 我们推导了18种元素的恒星动力学特性、大气参数和丰度。 锂线测量被用作近似年龄估计。 我们利用化学丰度及其比值来获取有关行星组成的更多信息。 元素丰度和动力学特性与附近的银河薄盘一致。 所有目标均显示C/O<0.8，且1.0<Mg/Si<1.5，与由辉石和橄榄石组合构成的硅酸盐地幔相兼容。 Fe/Mg比值范围为$\sim$0.7-1.0，表明行星倾向于具有较大的（铁）核心。 所有宿主极低质量行星的恒星显示Mg/Si值与地球值一致，从而证明它们的地幔组成相似。 热木星宿主恒星显示较低的O/Si含量，这可能与水含量较低相关。 我们确认了文献中关于恒星[O/Fe]与总行星质量之间的趋势，这意味着氧在决定恒星及其盘中重元素的质量分数方面起着重要作用。 当利用当前样本中的行星大气时，所提供的详细宿主恒星丰度可用于进一步研究这些行星的组成。 显示英文摘要

摘要： The study of exoplanets at different evolutionary stages can shed light on their formation, migration, and evolution. The determination of exoplanet properties depends on the properties of their host stars. It is therefore important to characterise the host stars for accurate knowledge on their planets. Our final goal is to derive, in a homogeneous and accurate way, the stellar atmospheric parameters and elemental abundances of ten young TESS transiting planet-hosting GK stars followed up with the HARPS-N at TNG spectrograph within the GAPS programme. We derived stellar kinematic properties, atmospheric parameters, and abundances of 18 elements. Lithium line measurements were used as approximate age estimations. We exploited chemical abundances and their ratios to derive information on planetary composition. Elemental abundances and kinematic properties are consistent with the nearby Galactic thin disk. All targets show C/O<0.8 and 1.0<Mg/Si<1.5, compatible with silicate mantles made of a mixture of pyroxene and olivine assemblages. The Fe/Mg ratios, with values of $\sim$0.7-1.0, show a propensity for the planets to have big (iron) cores. All stars hosting very low-mass planets show Mg/Si values consistent with the Earth values, thus demonstrating their similar mantle composition. Hot Jupiter host stars show a lower content of O/Si, which could be related to the lower presence of water content. We confirm a trend found in the literature between stellar [O/Fe] and total planetary mass, implying an important role of the O in shaping the mass fraction of heavy elements in stars and their disks. The detailed host star abundances provided can be employed for further studies on the composition of the planets within the current sample, when their atmospheres will be exploited.