Related papers: Planets, debris and their host metallicity correla…
Planets with sizes between those of Earth and Neptune divide into two populations: purely rocky bodies whose atmospheres contribute negligibly to their sizes, and larger gas-enveloped planets possessing voluminous and optically thick…
I discuss the role that disc fragmentation plays in the formation of gas giant and terrestrial planets, and how this relates to the formation of brown dwarfs and low-mass stars, and ultimately to the process of star formation. Protostellar…
Intermediate mass planets, from Super-Earth to Neptune-sized bodies, are the most common type of planets in the galaxy. The prevailing theory of planet formation, core-accretion, predicts significantly fewer intermediate-mass giant planets…
Trends in the planet population with host star mass provide an avenue to constrain planet formation theories. We derive the planet radius distribution function for Kepler stars of different spectral types, sampling a range in host star…
Understanding the relationship between close-in small planets (CS) and distant giants (DG) is central to understanding the formation of planetary systems like our own. Most studies of this connection have found evidence for a positive…
Planet searches around evolved giant stars are bringing new insights to planet formation theories by virtue of the broader stellar mass range of the host stars compared to the solar-type stars that have been the subject of most current…
"Debris disks" around young stars (analogues of the Kuiper Belt in our Solar System) show a variety of non-trivial structures attributed to planetary perturbations and used to constrain the properties of the planets. However, these analyses…
The commonality of collisionally replenished debris around main sequence stars suggests that minor bodies are frequent around Sun-like stars. Whether or not debris disks in general are accompanied by planets is yet unknown, but debris disks…
It has recently been noted that many discs around T Tauri stars appear to comprise only a few Jupiter-masses of gas and dust. Using millimetre surveys of discs within six local star-formation regions, we confirm this result, and find that…
Recent detailed observations of protoplanetary discs revealed a lot of sub-structures which are mostly ring-like. One interpretation is that these rings are caused by growing planets. These potential planets are not yet opening very deep…
The prevalence of short-period super-Earths that are independent of host metallicity challenges the theoretical construction of their origin. We propose that dust trapping in the global pressure bump induced by magnetospheric truncation in…
Depending on the stellar densities, protoplanetary discs in stellar clusters undergo background heating, disc truncation-driven by stellar encounter, and photo-evaporation. Disc truncation leads to reduced characteristic sizes and disc…
It is often argued that gravitational instability of realistic protoplanetary discs is only possible at distances larger than $\sim 50$ au from the central star, requiring high disc masses and accretion rates, and that therefore disc…
This work presents a homogeneous derivation of atmospheric parameters and iron abundances for a sample of giant and subgiant stars which host giant planets, as well as a control sample of subgiant stars not known to host giant planets. The…
According to core-accretion formation models, the conditions under which gas giants will form around M dwarfs are very restrictive. Also, the correlation of the occurrence of these planets with the metallicity of host stars is still unknown…
A significant fraction of the mature FGK stars have cool dusty disks at least an orders of magnitudes brighter than the solar system's outer zodiacal light. Since such dusts must be continually replenished, they are generally assumed to be…
We hypothesise that planets are made by tidal downsizing of migrating giant planet embryos. The proposed scheme for planet formation consists of these steps: (i) a massive young protoplanetary disc fragments at R ~ several tens to hundreds…
The formation of planetary cores must proceed rapidly in order for the giant planets to accrete their gaseous envelopes before the dissipation of the protoplanetary gas disc (<3 Myr). In orbits beyond 10 AU, direct accumulation of…
Most stars are born in clusters and the resulting gravitational interactions between cluster members may significantly affect the evolution of circumstellar discs and therefore the formation of planets and brown dwarfs. Recent findings…
Dust in protoplanetary disks is recognized as the building blocks of planets. In the core accretion scenario, the abundance of dust in disks (or metallicity) is crucial for forming cores of gas giants. We present our recent progress on the…