A5060844024- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Planetary Science and Exploration
- Scientific Research and Discoveries
- High-pressure geophysics and materials
- Astronomical Observations and Instrumentation
- Adaptive optics and wavefront sensing
- Spacecraft and Cryogenic Technologies
- Paleontology and Stratigraphy of Fossils
- Inertial Sensor and Navigation
- Tribology and Lubrication Engineering
- Methane Hydrates and Related Phenomena
- Gas Dynamics and Kinetic Theory
- Space Exploration and Technology
- Astronomical and nuclear sciences
- Molecular Spectroscopy and Structure
- Geological and Geophysical Studies
- Distributed and Parallel Computing Systems
- Geology and Paleoclimatology Research
- Solar and Space Plasma Dynamics
- Advanced Semiconductor Detectors and Materials
- Geophysics and Gravity Measurements
Max Planck Institute for Astronomy
2018-2025
University of Bern
2018-2024
Max Planck Society
2018
Purdue University West Lafayette
1970
Context. Previous theoretical works on planet formation around low-mass stars have often been limited to large planets and individual systems. As current surveys routinely detect down terrestrial size in these systems, models shifted toward a more holistic approach that reflects their diverse architectures. Aims. Here, we investigate identify differences the statistical distribution of modeled planets. We compare synthetic populations observed exoplanets discuss identified trends. Methods....
Aims. Comparing theoretical models with observations allows one to make key step forward towards an understanding of planetary systems. It however requires a model able (i) predict all the necessary observable quantities (not only masses and orbits, but also radii, luminosities, magnitudes, or evaporation rates) (ii) address large range in relevant (from Mars mass super-Jupiters) distances stellar-grazing wide orbits). Methods. We have developed combined global end-to-end formation evolution...
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 The radius valley (or gap) in the observed distribution of exoplanet radii, which separates smaller super-Earths from larger sub-Neptunes, is a key feature that theoretical models must explain. Conventionally, it interpreted as result loss primordial hydrogen and helium (H/He) envelopes atop rocky cores. However, planet formation predict water-rich planets migrate cold regions outside snowline towards star. Assuming water to be form solid ice their interior, many these would located...
Context. Planetary formation and evolution is a combination of multiple interlinked processes. Constraining the mechanisms observationally requires statistical comparison to large diversity planetary systems. Aims. We want understand global observable consequences different physical processes (accretion, migration, interactions) initial properties (like disc masses metallicities) on demographics population. also study convergence our scheme with respect one condition, number embryo in each...
Recent observational findings have suggested a positive correlation between the occurrence rates of inner super-Earths and outer giant planets. These results raise question whether this trend can be reproduced explained by planet formation theory. Here, we investigate properties planets that form according to core accretion scenario. We study mutual relations these species in synthetic planetary systems compare them observed exoplanet population. invoked Generation 3 Bern model evolution...
Context. Planet formation is sensitive to the conditions in protoplanetary disks, for which scaling laws as a function of stellar mass are known. Aims. We aim test whether observed population planets around low-mass stars can be explained by these trends, or if separate channels needed. Methods. address this question confronting state-of-the-art planet synthesis model with sample M dwarfs HARPS and CARMENES radial velocity (RV) surveys. To account detection biases, we performed injection...
Context. State-of-the-art planet formation models are now capable of accounting for the full spectrum known types. This comes at cost an increasing complexity models, which calls into question whether established links between their initial conditions and calculated planetary observables preserved. Aims. In this paper, we take a data-driven approach to investigate relations clusters synthetic planets with similar properties history. Methods. We trained Gaussian mixture model on typical...
We present the discovery of an Earth-mass planet ( M b sin i = 1.26 ± 0.21 ⊕ ) on a 15.6 d orbit relatively nearby ~ 9.6 pc) and low-mass (0.167 0.011 ⊙ M5.0 V star, Wolf 1069. Sitting at separation 0.0672 0.0014 au away from host star puts 1069 in habitable zone (HZ), receiving incident flux S 0.652 0.029 . The planetary signal was detected using telluric-corrected radial-velocity (RV) data CARMENES spectrograph, amounting to total 262 spectroscopic observations covering almost four years....
Planetary population synthesis is a tool to understand the physics of planetary system formation. It builds on model that includes multitude physical processes. The outcome can be statistically compared with exoplanet observations. Here, we review method and then use one explore how different architectures emerge which conditions lead their systems classified into four main architectures: Class I near-in situ compositionally ordered terrestrial ice planets, II migrated sub-Neptunes, III...
We re-determine planetary occurrences around M dwarfs using 20 years of observations from HARPS on 197 targets. The first aim this study is to propose more precise occurrence rates the large volume sample but also variations previous calculations, particularly by considering multiplicity, which now an integral part calculations. second exploit extreme longevity determine in unexplored domain very long periods. This work relies entirely radial velocity time series obtained and analysed our...
Statistical analyses from exoplanet surveys around low-mass stars indicate that super-Earth and Neptune-mass planets are more frequent than gas giants such stars, in agreement with core accretion theory of planet formation. Using precise radial velocities derived visual near-infrared spectra, we report the discovery a giant minimum mass 0.46 Jupiter masses an eccentric 204-day orbit very star GJ 3512. Dynamical models show high eccentricity is most likely explained planet-planet...
Large sub-Neptunes are uncommon around the coolest stars in Galaxy and rarer still those that metal-poor. However, owing to large planet-to-star radius ratio, these planets highly suitable for atmospheric study via transmission spectroscopy infrared, such as with JWST. Here we report discovery validation of a sub-Neptune orbiting thick-disk, mid-M dwarf star TOI-2406. We first infer properties host by analysing star's near-infrared spectrum, spectral energy distribution, Gaia parallax. use...
Aims . We want to find the distribution of initial conditions that best reproduces disc observations at population level. Methods first ran a parameter study using 1D model includes viscous evolution gas disc, dust, and pebbles, coupled with an emission compute millimetre flux observable ALMA. This was used train machine learning surrogate can relevant quantity for comparison in seconds. perform studies synthetic populations. Results Performing study, we internal photoevaporation leads lower...
NCORES was a large observing program on the ESO HARPS spectrograph, dedicated to measuring masses of Neptune-like and smaller transiting planets discovered by TESS satellite using radial velocity technique. This paper presents an overview programme, its scientific goals published results, covering 35 in 18 planetary systems. We present spectrally derived stellar characterisation mass constraints for five additional TOIs where observations found only marginally significant signals...
Abstract NCORES was a large observing program on the ESO HARPS spectrograph, dedicated to measuring masses of Neptune-like and smaller transiting planets discovered by TESS satellite using radial velocity technique. This paper presents an overview programme, its scientific goals published results, covering 35 in 18 planetary systems. We present spectrally derived stellar characterisation mass constraints for five additional TOIs where observations found only marginally significant signals...
Abstract The TOI-431 system has three close-in exoplanets, which gives an ideal lab to study gas escape. In this study, we measure the X-ray and ultraviolet luminosity for with XMM-Newton’s European Photon Imaging Camera-pn Optical/UV Monitor Telescope data, then calculate fluxes planets in system. We find b’s <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>F</mml:mi> <mml:mrow> <mml:mi>XUV</mml:mi> <mml:mo>,</mml:mo> <mml:mi...
TOI-431 system has 3 close-in exoplanets, which gives an ideal lab to study gas escape. In this study, we measure the XUV luminosity for with XMM-Newton/EPIC-pn and OM data, then calculate fluxes planets in system. We find that, b's $\rm F_{XUV,b}=$$70286^{+12060}_{-2611}$$\rm \ erg\ cm^{-2}s^{-1}$ is 75 times of d F_{XUV,d}=$$935^{+160}_{-35}$$\rm cm^{-2}s^{-1}$. Adopting energy limit method hydrodynamic code $ATES$ a set He/H ratios, obtain mass-loss rates $10^{10.51^{+0.07}_{-0.02}}$ g...
Previous estimates of planet occurrence rates in the CARMENES survey indicated increased numbers planets on short orbits for M dwarfs with masses below 0.34,M_⊙. Here we focused lowest-mass stars survey, comprising 15 inactive targets under 0.16,M_⊙. To correct detection biases, determined sensitivity maps individual and entire sample. Using Monte Carlo simulations, estimated orbital periods 1,d to 100,d minimum from 0.5,M_⊕ 10,M_⊕. We also compared actual sample known model predictions. The...
Context. In the core accretion scenario of giant planet formation, a massive forms first and then accretes gaseous envelope. discussion how this forms, some divergences appear. The scenarios formation predict kilometre-sized bodies called planetesimals, while more recent works suggest growth by pebbles, which are centimetre-sized objects. Aims. These two models often discussed separately our aim here is to compare outcomes with identical initial conditions. Methods. comparison done using...
(abridged) Observations of exoplanets indicate the existence several correlations in architecture planetary systems. Exoplanets within a system tend to be similar size and mass, evenly spaced, are often ordered mass. Small planets frequently packed tight configurations, while large have wider orbital spacing. Together, these called peas pod trends In this paper investigated theoretically simulated systems compared with observations. Whether emerge from astrophysical processes or detection...
A systematic, population-level discrepancy exists between the densities of exoplanets whose masses have been measured with transit timing variations (TTVs) versus those radial velocities (RVs). Since TTV planets are predominantly nearly resonant, it is still unclear whether attributed to detection biases or astrophysical differences resonant and non planet populations. We defined a controlled, unbiased sample 36 sub-Neptunes characterised by Kepler, TESS, HARPS, ESPRESSO. found that their...