A5025689440- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Planetary Science and Exploration
- Atmospheric Ozone and Climate
- Space Exploration and Technology
- Gamma-ray bursts and supernovae
- Methane Hydrates and Related Phenomena
- Solar and Space Plasma Dynamics
- Atmospheric and Environmental Gas Dynamics
- Spectroscopy and Laser Applications
- Hydrocarbon exploration and reservoir analysis
- Historical Astronomy and Related Studies
- Molecular Spectroscopy and Structure
- Phase Equilibria and Thermodynamics
- Energy Load and Power Forecasting
- High-pressure geophysics and materials
- Laser-induced spectroscopy and plasma
- Geochemistry and Geologic Mapping
- History and Developments in Astronomy
Institute of Astronomy
2022-2024
KU Leuven
2021-2024
University of Copenhagen
2021-2023
Max Planck Institute for Astronomy
2021-2022
Heidelberg University
2018
Constraining planet formation based on the atmospheric composition of exoplanets is a fundamental goal exoplanet community. Existing studies commonly try to constrain abundances, or analyze what abundance patterns given description predicts. However, there also pressing need develop methodologies that investigate how transform compositions into planetary inferences. In this study we summarize complexities and uncertainties state-of-the-art models they influence compositions. We introduce...
Abstract Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on nightside molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum hot Jupiter WASP-43b measured from 5 μm to 12 JWST’s Mid-Infrared Instrument. The spectra reveal large day–night temperature contrast (with...
Recent observations of extrasolar gas giants suggest super-stellar C/O ratios in planetary atmospheres, while interior models observed giant planets additionally high heavy element contents. Furthermore, recent protoplanetary disks revealed super-solar C/H ratios, which are explained by inward drifting and evaporating pebbles, enhancing the volatile content disk. We investigate how drift evaporation rich pebbles influences atmospheric ratio growing pebble accretion. To achieve this goal, we...
Upcoming studies of extrasolar gas giants will give precise insights into the composition planetary atmospheres with ultimate goal to link it formation history planet. Here, we investigate how drifting and evaporating pebbles that enrich phase disk influence chemical growing migrating giants. To achieve this goal, perform semi analytical 1D models protoplanetary disks including viscous evolution, pebble drift evaporation simulate growth planets from embryos Jupiter mass objects by accretion...
In the pebble accretion scenario, pebbles that form planets drift inward from outer disk regions, carrying water ice with them. At line, on drifting evaporates and is released into gas phase, resulting in water-rich dry move inner regions. Large planetary cores can block by forming a pressure bump outside their orbit protoplanetary disk. Depending relative position of growing core to might be blocked or inside line. Pebbles line do not evaporate thus release vapor disk, while diffusing As...
Simulations with a 3D general circulation model (GCM) suggest that one potential driver behind the observed radius inflation in hot Jupiters may be downward advection of energy from highly irradiated photosphere into deeper layers. Here, we compare dynamical heat transport within non-inflated Jupiter WASP-43b and canonical inflated HD 209458b, similar effective temperatures. We investigate to what extent radiatively driven heating cooling (at pressures smaller than 1 bar) influence...
Atmospheric abundances are thought to constrain the planet formation pathway, because different species evaporate at temperatures leaving distinct signatures in accreted atmosphere. The planetary C/O ratio is of condensation sequence H$_2$O, CO$_2$, CH$_4$, and CO, resulting an increase gas phase with increasing distance. Here we use a disc evolution model including pebble growth, drift evaporation coupled that includes accretion as well migration compute atmospheric compositions giant...
Elucidating the radiative-dynamical coupling between upper photosphere and deeper atmosphere may be key to our understanding of abnormally large radii hot Jupiters. Very long integration times 3D general circulation models (GCMs) with self-consistent radiative transfer are needed obtain a more comprehensive picture feedback processes dynamics radiation. Here, we present longest nongray GCM study date (86000 d) an ultra-hot Jupiter (WASP-76 b) that has reached final converged state....
WASP-96b is a hot Saturn exoplanet, with an equilibrium temperature well within the regime of thermodynamically expected extensive cloud formation. Prior observations Hubble/WFC3, Spitzer/IRAC, and VLT/FORS2 have been combined into single spectra for which retrievals suggest cold but cloud-free atmosphere. Recently, planet was observed James Webb Space Telescope (JWST) as part Early Release Observations (ERO). 1D profiles are extracted from 3D GCM expeRT/MITgcm results used input kinetic,...
Understanding the discrepancy between radii of observed hot Jupiters and standard 'radiative-convective' models remains a hotly debated topic in exoplanet community. One mechanism which has been proposed to bridge this gap, recently come under scrutiny, is vertical advection potential temperature from irradiated outer atmosphere deep into interior, heating deep, unirradiated, atmosphere, warming internal adiabat, resulting radius inflation. Specifically, recent study explored WASP-76b using...
Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models predict that clouds may condense on nightside molecular abundances can be driven out of equilibrium by zonal winds. Here we report a phase-resolved emission spectrum hot Jupiter WASP-43b measured from 5-12 $μ$m JWST's Mid-Infrared Instrument (MIRI). The spectra reveal large day-night temperature contrast (with...
Context. Recent observations have resulted in the detection of chemical gradients on ultra-hot gas giants. Notwithstanding their high temperature, reactions atmospheres may occur disequilibrium, due to vigorous day-night circulation and intense UV radiation from stellar hosts. Aims. The goal this work is explore whether photochemistry affecting composition giant planets, if it can introduce horizontal gradients. In particular, we focus hydrogen cyanide (HCN) WASP-76 b, as a photochemically...
The possibility of observing spectral features in exoplanet atmospheres with space missions like the James Webb Space Telescope (JWST) and Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL) necessitates accurate modelling cloud particle opacities. In atmospheres, particles can be made from multiple materials considerably chemically heterogeneous. Therefore, assumptions on morphology are required to calculate their aim this work is analyse how different approaches opacities...
Context . In this paper we present a grid of self-consistent 1D model atmospheres cool stars, sub-stellar objects, and exoplanets in the effective temperature range 300-3000 K, including cloud formation, chemical non-equilibrium effects, stellar irradiation. Aims The new extends classical MARCS atmosphere from 2008 towards lower temperatures broader object types. Methods computations, MSG, are based on combination three well-tested codes, atmospheres, StaticWeather formation code, GGchem...
With observatories such as JWST, astronomers are now attempting to better understand the previously inscrutable atmospheres of mini-Neptunes, smaller and often cooler cousins better-studied hot Jupiters. General circulation models (GCMs) an essential part toolset used improve that understanding, from both perspective theoretical investigations in support observation. It is only recently, however, exoplanet community has begun benchmark study behaviour our GCMs through intercomparisons, a...
Of the many recently discovered terrestrial exoplanets, some are expected to harbor moderate water mass fractions of a few percent. The formation pathways that can produce planets with these not fully understood. Here, we use code chemcomp, which consists semi-analytical 1D protoplanetary disk model harboring migrating and accreting planet, growth composition by pebble accretion in around TRAPPIST-1 analog star. This star is accompanied seven planets, outer four likely contain between 1\%...
WASP-39b is one of the first extrasolar giant gas planets that has been observed within JWST ERS program. Fundamental properties may enable link to exoplanet formation differ amongst retrieval methods, for example metallicity and mineral ratios. In this work, clouds in atmosphere explored investigate how inhomogeneous cloud (particle sizes, material composition, opacity) be intermediately warm gaseous exoplanet. WASP-39b's a comparable day-night temperature median with sufficiently low...
To understand high precision observations of exoplanets and brown dwarfs, we need detailed complex general circulation models (GCMs) that incorporate hydrodynamics, chemistry, radiation. For this study, specifically examined the coupling between chemistry radiation in GCMs compared different methods for mixing opacities chemical species correlated-k assumption, when equilibrium cannot be assumed. We propose a fast machine learning method based on DeepSets (DS), which effectively combines...
Recent observations have resulted in the detection of chemical gradients on ultra-hot gas giants. Notwithstanding their high temperature, reactions atmospheres may occur disequilibrium, due to vigorous day-night circulation and intense UV radiation from stellar hosts. The goal this work is explore whether photochemistry affecting composition giant planets, if it can introduce horizontal gradients. In particular, we focus hydrogen cyanide (HCN) WASP-76 b, as a photochemically active molecule...
Computation of a grid self consistent 1D model atmospheres cool stars, sub-stellar objects and exoplanets in the effective temperature range 300K to 3000K, including cloud formation, chemical non-equilibrium effects, stellar irradiation. The models are called MSG, because they based on an iterative coupling between three well tested codes, MARCS atmosphere code, StaticWeather formation code GGchem equilibrium code. It includes up-to-date molecular atomic opacities, advanced calculations,...
Understanding the discrepancy between radii of observed hot Jupiters and standard 'radiative-convective' models remains a hotly debated topic in exoplanet community. One mechanism which has been proposed to bridge this gap, recently come under scrutiny, is vertical advection potential temperature from irradiated outer atmosphere deep into interior, heating deep, unirradiated, atmosphere, warming internal adiabat, resulting radius inflation. Specifically, recent study explored WASP-76b using...
The chemical fingerprint of a planet can reveal information about its formation history regarding when and where the formed. In particular, water content help to constrain pathway: If formed in outer regions disk migrated inward, it would be water-rich due accretion water-ice-rich solids. Conversely, inner region, water-ice is not available, result smaller atmospheric limited vapor. However, this process becomes complex with presence gap-opening giant planets. A gas exerts pressure bump...
Eccentric exoplanets offer an opportunity to study the response of atmosphere changing thermal forcing and robustness super-rotating equatorial jet seen on tidally locked hot Jupiters. However, atmospheric dynamics eccentric planets strongly depend planetary rotation period, which is difficult constrain observationally. The ringing phenomenon, whereby observed emission increases decreases after periastron passage as flash-heated hemisphere rotates into out view, can provide a tight...