Description
By better understanding how a planetary system was formed and evolved into the currently observed configuration, we can put constraints on the planetary composition and initial planetary disk. We can also determine if the climates of the planets in the habitable zone can be stable over billions of years such that life can develop.
Despite the discovery of thousands of close-in sub-Neptune exoplanets in our galaxy to date, their exact nature continues to be a point of debate. The uncertainty in their compositions generally results from the inherent degeneracies in their mass-radius diagram. Recent work demonstrating that significant amounts of water can be produced endogenically by hydrogen magma-ocean interactions...
Close-in exoplanets are shaped by complex atmospheric and dynamical processes, to which exo-Neptunes appear to be particularly sensitive. While atmospheric erosion played a major role in forming the Neptunian "Desert" (a dearth of hot Neptunes at short orbital periods), it is not clear how far into the "Savanna" (a milder deficit of warm Neptunes at longer periods) this process is active and...
Atmospheric and dynamical processes are thought to play a major role in shaping the distribution of close-in exoplanets. A striking feature of such distribution is the Neptunian desert, a dearth of Neptunes on the shortest-period orbits. We aimed to define the boundaries of the Neptunian desert and study its transition into the savanna, a moderately populated region at larger orbital...
To date there have been already 724 binary star systems discovered, which inhabit at least one planet. Most studies that have investigated the late stage of terrestrial planet formation in binary stars considered planar configurations, which might be accurate for tight binary stars. However, for wide binary stars it is assumed, that the inclination between the two stars is randomly...
We present the results of a new and comprehensive approach to simulating the formation of terrestrial planets. Our approach begins with simulating the collisional growth of the first planetesimals and continues with resolving giant impacts using our state-of-the-art SPH-based model. We take into account all relevant physical processes including the dynamical friction due to the debris and...
Using a homogeneous analysis approach, we present a comprehensive study of close-in Neptune-sized planets. We compile a well-defined sample of TESS-observed planets, ranked based on their orbital period, radius, and the visual magnitude of their host stars. To ensure precise radial velocity measurements, we incorporate archival and new HARPS data, resulting in a final sample of 64 targets—46...
TRAPPIST-1 hosts seven planets. The period ratios of neighbouring pairs are close to the 8:5, 5:3, 3:2, 3:2, 4:3 and 3:2 ratios in increasing distance from the star. The Laplace angles associated with neighbouring triplets are observed to be librating, proving the resonant nature of the system. This compact, resonant configuration is a manifest sign of disk-driven migration; however, the...
Planetary systems in resonant chains are of particular interest both from a dynamical point of view and an observational point of view. In particular the three planet resonant angles are a valuable observable for transiting systems. Indeed, transit timing observations allow to measure the libration of these angles while in most cases the two planet angles cannot be observed. The final...
The formation of hot Jupiters remains an open question, with many proposed mechanisms well-suited to explain subsets of the observed population. Notably, the traditional high-eccentricity migration mechanism driven by a distant stellar companion is one of the oldest hot Jupiter formation channels, and it is often cited as the formation mechanism for hot Jupiters on high-obliquity orbits....
Two leading hypotheses of hot Jupiter formation are disk migration, where a Jupiter in the outer part of the disk and migrates inward due to gas drag, and high eccentricity migration (HEM), where a Jupiter is excited to an eccentric orbit by its stellar or planetary companion and subsequently circularizes close to the pericenter distance due to tidal dissipation in the planet. Measurement of...
The sub-Neptune population currently poses a conundrum. Are the smallest sub-Neptunes "gas dwarfs" (Earth-like cores surrounded by H/He envelopes) or "water worlds" (planets composed of ice and rock that migrated inward after forming beyond the snow line)? And if both populations exist, what are their distinguishing properties, and how do they depend on stellar type? Recent studies propose...
One of the primary and long-standing goals of the planetary science community is to understand planet formation and evolution. Most studies so far have been limited to planets around fully evolved stars, including those in the Solar System. However, models predict that the major phases of planetary evolution—such as formation (<3 Myr), disk migration (<5 Myr), evolutionary cooling (3–400 Myr),...
Recent advancements in exoplanet detection have led to over 5,700 confirmed detections. The planetary systems hosting these exoplanets exhibit remarkable diversity. The position of the innermost planet (i.e., the inner edge) in a planetary system provides important information about the relationship of the entire system to its host star properties, offering potentially valuable insights into...
The formation and evolution of planetary systems are linked to their host stellar environment. Here we employ a pebble accretion planet formation model to explore the correlation between planetary properties and stellar mass/metallicity. Our numerical results reproduce several main aspects of exoplanetary observations. First, we find that the occurrence rate of super-Earths ηSE follows an...
Exoplanets and smaller bodies have been detected orbiting different kind of stars. However, we do not know of any such objects in planetary nebulae, the short-lived stage of stellar evolution between the asymptotic giant branch and white dwarf phases. The planetary activity (destruction and formation) may be accompanied by dust clouds. Hence, we searched for dust occultation events in...
The GJ 9827 system hosts three planets in near-resonant orbits, smaller than two Earth radii. The two inner planets have an Earth-like composition, while the outer companion is a mini-Neptune with a volatile envelope. These features raise questions about the roles of in-situ formation and inward migration in shaping the system, which can be addressed by measuring the orbital architectures of...
Planets in compact multi-transiting systems tend to exhibit self-similarity with their neighbors, a phenomenon commonly called "peas-in-a-pod". Previous studies have identified that this self-similarity appears independently among super-Earths and sub-Neptunes orbiting the same star. In this study, we investigate whether the peas-in-a-pod phenomenon holds for planets in the radius gap between...
