Related papers: A temperature condensation trend in the debris-dis…
Debris discs have often been described as gas-poor discs as the gas-to-dust ratio is expected to be considerably lower than in primordial,protoplanetary discs. However, recent observations have confirmed the presence of a non-negligible…
This article describes condensation of the elements and use of condensation temperatures (Tcond) to interpret the volatility trend of the Earth. Major points are: (1) a listing of updated 50% Tcond for all natural elements and Pu at 1e-2 to…
The temperature dependence of the linear thermal expansion coefficients (LTEC) of a single crystal of a-(BEDT-TTF)2NH4Hg(SCN)4 where BEDT-TTF is bis(ethylenedithio)tetrathiafulvalene was studied by the method of precision capacitive…
Beta Pic is a young, A5V star, known for harbouring a large number of exocomets, which frequently transit the star and produce absorption signatures. The physical and chemical properties of these exocomets can be probed by the recently…
Planetary engulfment events involve the chemical assimilation of a planet into a star's external layer. This can cause a change in the chemical pattern of the stellar atmosphere in a way that mirrors the composition of the rocky object…
The $\beta$ Pictoris system is characterized by a dusty debris disk, in addition to the presence of two already known planets. This makes it a particularly interesting case for studying the formation and evolution of planetary systems at a…
In this paper we study the evolution of viscous and radiative circumstellar disks under the influence of a companion star. We focus on the eccentric {\gamma} Cephei and {\alpha} Centauri system as examples and compare the disk quantities…
Stars in the solar neighbourhood have refractory element ratios slightly different from the Sun. It is unclear how much the condensation of solids and thus the composition of planets forming around these stars is affected. We aim to…
Transiting hot Jupiters present a unique opportunity to measure absolute planetary masses due to the magnitude of their radial velocity signals and known orbital inclination. Measuring planet mass is critical to understanding atmospheric…
Systematic abundance differences that depend on the condensation temperatures of elements have been observed, in particular for stars similar to the Sun; solar twins and solar analogs. Similar differences have also recently been shown to…
We present $\gtrsim 15,000$ metal-rich (${\rm [Fe/H]}>-0.2$dex) A and F stars whose surface abundances deviate strongly from Solar abundance ratios and cannot plausibly reflect their birth material composition. These stars are identified by…
We report on a programme to monitor the radial velocities of a sample of candidate and confirmed carbon-enhanced, metal-poor (CEMP) stars. We observed 45 targets using the Echelle Spectrographs of three 4m class telescopes. Radial…
Context: Since circumstellar dust in debris disks is short-lived, dust-replenishing requires the presence of a reservoir of planetesimals. These planetesimals in the parent belt of debris disks orbit their host star and continuously supply…
We present new UVES spectra of a sample of 15 cool unevolved stars with and without detected planetary companions. Together with previous determinations, we study Be depletion and possible differences in Be abundances between both groups of…
We analyze Spitzer IRS spectra of 110 B-, A-, F-, and G-type stars with optically thin infrared excess in the Scorpius-Centaurus (ScoCen) OB association. The age of these stars ranges from 11-17 Myr. We fit the infrared excesses observed in…
The mass of solids in a young circumstellar disc may be the key factor in its efficiency in building planetesimals and planetary cores, and dust observed around young T Tauri and Herbig Ae stars can be used as a proxy for this initial solid…
Planetary systems hold the imprint of the formation and of the evolution of planets especially at young ages, and in particular at the stage when the gas has dissipated leaving mostly secondary dust grains. The dynamical perturbation of…
Recent observational work by Israelian et al. has shown that sun-like planet host stars in the temperature range 5700K < Teff < 5850K have lithium abundances that are significantly lower than those observed for "single" field stars. In this…
The ultra-faint dwarf galaxy Reticulum II (Ret II) exhibits a unique chemical evolution history, with 72 +10/-12% of its stars strongly enhanced in r-process elements. We present deep Hubble Space Telescope photometry of Ret II and analyze…
To understand the formation of planetary systems, one needs to understand the initial conditions of planet formation, i.e. the young gas-rich planet forming disks. Spatially resolved high-contrast observations are of particular interest,…