The implications of clustered star formation for (proto)planetary systems and habitability

Nautilus: GKM恒星耀斑的快速时间分辨光谱及其对行星宜居性的影响

Nautilus: Fast Time-Resolved Spectroscopy of GKM Stellar Flares and Their Implications for Planetary Habitability

针对低质量恒星耀斑对行星大气的影响，提出Nautilus空间天文台概念，通过快速时间分辨光谱观测构建经验模板库，为行星大气演化与宜居性模拟提供辐射输入。

Modeling chemistry during star formation: Water deuteration in dynamic star-forming regions

Recent observations of the HDO/H$_2$O ratio toward protostars in isolated and clustered environments show an apparent dichotomy, where isolated sources show higher D/H ratios than clustered counterparts. Establishing which physical and chemical processes create this differentiation can provide insights into the chemical evolution of water during star formation and the chemical diversity during the star formation process and in young planetary systems. Methods: The evolution of water is modeled using 3D physicochemical models of a dynamic star-forming environment. The physical evolution during …

Earth-like Habitats in Planetary Systems

Understanding the concept of habitability is related to an evolutionary knowledge of the particular planet-in-question. Additional indications so-called "systemic aspects" of the planetary system as a whole governs a particular planet's claim on habitability. Here we focus on such systemic aspects and discuss their relevance to the formation of an 'Earth-like' habitable planet. We summarize our results obtained by lunar sample work and numerical models within the framework of the Research Alliance "Planetary Evolution and Life". We consider various scenarios which simulate the dynamical evolut…

论星团环境中低质量恒星周围巨行星形成的抑制

On the suppression of giant planet formation around low-mass stars in clustered environments

本研究通过基于卵石吸积的行星种群合成代码，模拟了星团环境对行星形成的影响，发现星团环境会抑制低质量恒星周围冷木星的形成并增加冷海王星数量，为未来观测约束行星诞生环境提供了潜在特征。

Statistical properties of habitable zones in stellar binary systems

Observations of exoplanets and protoplanetary disks show that binary stellar systems can host planets in stable orbits. Given the high binary fraction among stars, the contribution of binary systems to Galactic habitability should be quantified. Therefore, we have designed a suite of Monte Carlo experiments aimed at generating large (up to $10^6$) samples of binary systems. For each system randomly extracted we calculate the intersection between the radiative habitable zones and the regions of dynamical stability using published empirical formulations that account for the dynamical and radiati…

Can habitable planets form in clustered environments?

We present observational evidence of environmental effects on the formation and evolution of planetary systems. We combine catalogues of resolved protoplanetary discs (PPDs) and young stellar objects in the solar neighbourhood to analyse the PPD size distribution as a function of ambient stellar density. By running Kolmogorov-Smirnov tests between the PPD radii at different densities, we find empirical evidence, at the >97% confidence level, for a change in the PPD radius distribution at ambient stellar densities Σ> 10^{3.5} pc^{-2}. This coincides with a simple theoretical estimate for the tr…

Formation and composition of planets around very low mass stars

The recent detection of planets around very low mass stars raises the question of the formation, composition and potential habitability of these objects. We use planetary system formation models to infer the properties, in particular their radius distribution and water content, of planets that may form around stars ten times less massive than the Sun. Our planetary system formation and composition models take into account the structure and evolution of the protoplanetary disk, the planetary mass growth by accretion of solids and gas, as well as planet-planet, planet-star and planet-disk intera…

弥合紫外缺口：罗马、欧几里得和HWO时代的恒星形成科学的HST紫外基础

Bridging the UV Gap: The HST Ultraviolet Foundation for Star Formation Science in the Era of Roman, Euclid, and HWO

本文论证了在红外和光学巡天主导的未来，哈勃太空望远镜的紫外光谱仪对研究恒星形成、行星宜居性和恒星演化不可或缺，是通往宜居世界天文台的关键科学桥梁。

Close Stellar Encounters in Young, Substructured, Dissolving Star Clusters: Statistics and Effects on Planetary Systems

Both simulations and observations indicate that stars form in filamentary, hierarchically clustered associations, most of which disperse into their galactic field once feedback destroys their parent clouds. However, during their early evolution in these substructured environments, stars can undergo close encounters with one another that might have significant impacts on their protoplanetary disks or young planetary systems. We perform N-body simulations of the early evolution of dissolving, substructured clusters with a wide range of properties, with the aim of quantifying the expected number …

Global Models of Planet Formation and Evolution

Despite the increase in observational data on exoplanets, the processes that lead to the formation of planets are still not well understood. But thanks to the high number of known exoplanets, it is now possible to look at them as a population that puts statistical constraints on theoretical models. A method that uses these constraints is planetary population synthesis. Its key element is a global model of planet formation and evolution that directly predicts observable planetary properties based on properties of the natal protoplanetary disk. To do so, global models build on many specialized m…

Protoplanetary disc evolution affected by star-disc interactions in young stellar clusters

Most stars form in a clustered environment. Therefore, it is important to assess how this environment influences the evolution of protoplanetary discs around young stars. In turn, this affects their ability to produce planets and ultimately life. We present here for the first time 3D SPH/N-body simulations that include both the hydrodynamical evolution of the discs around their natal stars, as well as the dynamics of the stars themselves. The discs are viscously evolving, accreting mass onto the central star and spreading. We find penetrating encounters to be very destructive for the discs as …