Publications (23)
Assessing the processes behind planet engulfment and its imprints
B. M. T. B. Soares, V. Adibekyan, C. Mordasini +5
Throughout a planetary system's formation evolution, some of the planetary material may end up falling into the host star and be engulfed by it, leading to a potential variation of…
Matter accretion in metal-poor stars down to extremely metal-poor stars and the lithium problem
M. Deal, O. Richard, S. Vauclair
The formation and evolution of light elements in the Universe act as important cosmological constraints. It has long been assumed that the oldest stars of the Galaxy display the pr…
Thorough characterisation of the 16 Cygni system. Part II. Seismic inversions of the internal structure
G. Buldgen, M. Farnir, P. Eggenberger +5
The advent of space-based photometry observations provided high-quality asteroseismic data for a large number of stars. These observations enabled the adaptation of advanced techni…
Primordial nucleosynthesis with varying fundamental constants: Solutions to the Lithium problem and the Deuterium discrepancy
M. Deal, C. J. A. P. Martins
The success of primordial nucleosynthesis has been limited by the long-standing Lithium problem. We use a self-consistent perturbative analysis of the effects of relevant theoretic…
Dilution of accreted planetary matter in hot DA white dwarfs according to their mass
M. Deal, S. Vauclair, S. Charpinet +1
A large proportion of observed white dwarfs (WDs) show evidence of debris disks, remnants of the former planetary systems, and/or signatures of heavy elements in their atmospheres,…
Linking the primordial composition of planet building disks to the present-day composition of rocky exoplanets
V. Adibekyan, M. Deal, C. Dorn +16
The composition of rocky planets is strongly driven by the primordial materials in the protoplanetary disk, which can be inferred from the abundances of the host star. Understandin…
Sun-like stars unlike the Sun: Clues for chemical anomalies of cool stars
V. Adibekyan, E. Delgado-Mena, S. Feltzing +11
We present a summary of the splinter session "Sun-like stars unlike the Sun" that was held on 09 June 2016 as part of the Cool Stars 19 conference (Uppsala, Sweden). We discussed t…
Chemical mixing in low mass stars: I. Rotation against atomic diffusion including radiative accelerations
M. Deal, M-J. Goupil, J. P. Marques +2
When modelling stars with masses larger than 1.2Msun with no observed chemical peculiarity, atomic diffusion is often neglected because, on its own, it causes unrealistic surface a…
Hydrodynamical instabilities induced by atomic diffusion in A stars and their consequences
M. Deal, O. Richard, S. Vauclair
Aims. Atomic diffusion, including the effect of radiative accelerations on individual elements, leads to important variations of the chemical composition inside the stars. The accu…
Glitches in solar-like oscillating F-type stars: Possible contribution of non-linear terms
M. Deal, M. -J. Goupil, J. Philidet +3
The glitch signatures in for F-type stars (higher amplitude and period of the oscillatory component) are very different from those of G-type stars. The aim of this work i…
Fundamental properties of a selected sample of Ap stars: Inferences from interferometric and asteroseismic constraints
M. Deal, M. S. Cunha, Z. Keszthelyi +2
Magnetic fields influence the formation and evolution of stars and impact the observed stellar properties. Ap stars (magnetic A-type stars) are a prime example of this. Access to p…
Asteroseismology of the exoplanet-host F-type star 94 Ceti : impact of atomic diffusion on the stellar parameters
M. Deal, M. E. Escobar, S. Vauclair +3
A precision of order one percent is needed on the parameters of exoplanet-hosts stars in order to correctly characterize the planets themselves. This will be achieved by asteroseis…
Cesam2k20: A code for a new generation of stellar evolution models. I. Description of the code
L. Manchon, M. Deal, J. P. C. Marques +1
We present Cesam2k20, the latest version of the hydrostatic stellar evolution code CESAM originally developed by P. Morel and collaborators. Over the last three decades, it has und…
Accretion from debris disks onto white dwarfs : Fingering (thermohaline) instability and derived accretion rates
M. Deal, S. Deheuvels, G. Vauclair +2
Recent observations of a large number of DA and DB white dwarfs show evidence of debris disks, which are the remnants of old planetary systems. The infrared excess detected with \e…
Predicted asteroseismic detection yield for solar-like oscillating stars with PLATO
M. J. Goupil, C. Catala, R. Samadi +26
We determine the expected yield of detections of solar-like oscillations for the PLATO ESA mission. We used a formulation from the literature to calculate the probability of detect…
Entropy-calibrated stellar modeling: Testing and improving the use of prescriptions for entropy of adiabatic convection
L. Manchon, M. Deal, M. -J. Goupil +7
The modeling of convection is a long standing problem in stellar physics. Up-to-now, all ad hoc models rely on a free parameter alpha (among others) which has no real physical just…
Constraints on the properties of macroscopic transport in the Sun from combined lithium and beryllium depletion
G. Buldgen, A. Noels, A. M. Amarsi +5
Context. The Sun is a privileged laboratory of stellar evolution, thanks to the quality and complementary nature of available constraints. Using these observations, we are able to…
Thermohaline Instabilities Induced by Heavy Element Accretion onto White Dwarfs: Consequences on the Derived Accretion Rates
M. Deal, S. Vauclair, G. Vauclair
Heavy elements are observed in the atmospheres of many DA and DB white dwarfs, and their presence is attributed to the accretion of matter coming from debris disks. Several authors…
Discovery of a thin lithium plateau among metal-poor red giant branch stars
A. Mucciarelli, L. Monaco, P. Bonifacio +5
The surface lithium abundance A(Li) of warm metal-poor dwarf stars exhibits a narrow plateau down to [Fe/H]~-2.8 dex, while at lower metallicities the average value drops by 0.3 de…
Glitches in solar-like oscillating F-type stars: Theoretical signature of the base of the convective envelope on the ratios
M. Deal, M. -J. Goupil, M. S. Cunha +7
The transition between convective and radiative stellar regions is still not fully understood. The sharp variations in sound speed located in these transition regions give rise to…
Wildly Oscillating Stars -- Unexplained dense ridge-like frequency agglomerations in A and F type pulsators
V. Antoci, J. Labadie-Bartz, M. Swiech +14
We investigate the origin of the dense, ridge-like frequency clusters observed in a subset of A and F type pulsating stars, which we refer to as `wildly oscillating' stars (WOS). T…
Tess asteroseismology of the known planet host star Fornacis
M. B. Nielsen, W. H. Ball, M. R. Standing +22
The Transiting Exoplanet Survey Satellite (TESS) is observing bright known planet-host stars across almost the entire sky. These stars have been subject to extensive ground-based o…
Impacts of radiative accelerations on solar-like oscillating main-sequence stars
M. Deal, G. Alecian, Y. Lebreton +5
Chemical element transport processes are among the crucial physical processes needed for precise stellar modelling. Atomic diffusion by gravitational settling nowadays is usually t…