Conveners
Advances in planet formation
- Hans Deeg
- Giampaolo Piotto
Planetary system architectures represent an additional class of observational constraints to planet formation and evolution theory besides the ones coming from the overall demographics of (individual) planets and the precise characterisation of specific planets. Examples are the frequency of mean motion resonances, correlations regarding the presence of different planet types within one system...
Stellar atmospheres serve as a crucial gateway to understanding the primordial composition of planetary systems. As planet-forming disks dissipate within a few million years, stellar observations become the primary means to probe their remnants. While conventional models assume a direct correspondence between the compositions of rocky exoplanets and their host stars, recent work by Adibekyan...
Traditionally, star formation and planet formation have been studied independently. However, we now know that the first phase of stellar evolution is affected by the accretion from protoplanetary disks. Planet formation theory predicts that the composition of the gas accreted by the star must have been variable: the growth and inward drift of dust in the disk leads to a "pebble wave" of...
The migration of planets through disc-planet interactions is likely to be important during planet formation. Evidence for migration is provided by systems of multiple exoplanets in which planets are in mean motion resonances and by the orbital configurations of circumbinary planets. However, attempts to reproduce the known population of exoplanets by planetary population synthesis models that...
The exoplanet population with relatively short orbital periods around solar-type stars is dominated by small planets (SPs), i.e. super-Earths and sub-Neptunes. These planets are, however, missing in our Solar System, and the reason for that is unknown. By studying the impact of cold Jupiters (CJs) on the formation and/or migration of SPs, several theoretical works have predicted either an...
Stars with astrometric signatures such astrometric acceleration from Gaia or Gaia-Hipparcos proper motion anomaly are known to host additional companions at close separations. In some cases these signatures are due to substellar and even planetary-mass companions, otherwise they are due to stellar companions at separation from a few AU to about 100-200 au. Such companions in some cases are...
By characterizing precisely both exoplanet and parent star and their age, PLATO will bring a new perspective to the study of exoplanets and the understanding of their evolution and formation history. For planets with large atmosphere, their progressive cooling and contraction may be constrained. The possibility to measure secondary eclipses and infer eccentricities of close-in planets means...
Although PLATO is focussed on the detection of small, rocky planets in the habitable zone, there is much still to learn about giant planets, and PLATO will make a significant contribution here. One unsolved problem is the origins of warm Jupiters (WJs). If they formed beyond the snow line, far from their host stars, then migration is required to bring them to their current orbits. It is...
