Publications (58)
Analysis of the linear approximation of seismic inversions for various structural pairs
G. Buldgen, D. R. Reese, M. A. Dupret
Thanks to space-based photometry missions CoRoT and Kepler, we benefit from a wealth of seismic data for stars other than the sun. In the future, K2, Tess, and Plato will complemen…
Convective core sizes in rotating massive stars: I. Constraints from solar metallicity OB field stars
S. Martinet, G. Meynet, S. Ekström +11
Spectroscopic studies of Galactic O and B stars show that many stars with masses above 8 M are observed in the HR diagram just beyond the Main-Sequence (MS) band predicte…
Asteroseismology of evolved stars to constrain the internal transport of angular momentum II. Test of a revised prescription for transport by the Tayler instability
P. Eggenberger, J. W. den Hartogh, G. Buldgen +3
Context: Asteroseismic measurements reveal that an unknown efficient angular momentum (AM) transport mechanism is needed for subgiant and red giant stars. A revised prescription fo…
Constraints on the structure of 16 Cyg A and 16 Cyg B using inversion techniques
G. Buldgen, D. R. Reese, M. A. Dupret
Constraining mixing processes and chemical composition is a central problem in stellar physics as their impact on stellar age determinations leads to biases in our studies of stell…
Detailed seismic study of Gemma (KIC11026764) using EGGMiMoSA: Unveiling the probing potential of mixed modes for subgiant stars
M. Farnir, M. -A. Dupret, G. Buldgen
Context. When leaving the main sequence (MS) for the red-giant branch (RGB), subgiant stars undergo fast structural changes. Consequently, their observed oscillation spectra mirror…
MCMC inversions of the internal rotation of Kepler subgiants
G. Buldgen, L. Fellay, J. Bétrisey +3
The measurement of the internal rotation of post-main sequence stars using data from space-based photometry missions has demonstrated the need for an efficient angular momentum tra…
Asteroseismology of evolved stars to constrain the internal transport of angular momentum. I. Efficiency of transport during the subgiant phase
P. Eggenberger, S. Deheuvels, A. Miglio +9
Context: The observations of solar-like oscillations in evolved stars have brought important constraints on their internal rotation rates. To correctly reproduce these data, an eff…
Combining multiple structural inversions to constrain the Solar modelling problem
G. Buldgen, S. J. A. J. Salmon, A. Noels +12
The Sun is the most studied of all stars. It is a reference for all other observed stars and a laboratory of fundamental physics helping us understand processes occuring in conditi…
Coralie radial-velocity search for companions around evolved stars (CASCADES) III. A new Jupiter host-star: in-depth analysis of HD 29399 using TESS data
C. Pezzotti, G. Ottoni, G. Buldgen +11
Context. Increasing the number of detected exoplanets is far from anecdotal, especially for long-period planets that require a long duration of observation. More detections imply a…
Seismic Solar Models from Ledoux discriminant inversions
G. Buldgen, P. Eggenberger, V. A. Baturin +6
The Sun constitutes an excellent laboratory of fundamental physics. With the advent of helioseismology, we were able to probe its internal layers with unprecedented precision. Howe…
Asteroseismology of evolved stars to constrain the internal transport of angular momentum. IV. Internal rotation of Kepler 56 from an MCMC analysis of the rotational splittings
L. Fellay, G. Buldgen, P. Eggenberger +4
The observations of global stellar oscillations of post main-sequence stars by space-based photometry missions allowed to directly determine their internal rotation. These constrai…
CORALIE radial-velocity search for companions around evolved stars (CASCADES). I. Sample definition and first results: Three new planets orbiting giant stars
G. Ottoni, S. Udry, D. Ségransan +11
Context. Following the first discovery of a planet orbiting a giant star in 2002, we started the CORALIE radial-velocity search for companions around evolved stars (CASCADES). We p…
SpaceInn hare-and-hounds exercise: Estimation of stellar properties using space-based asteroseismic data
D. R. Reese, W. J. Chaplin, G. R. Davies +15
Context: Detailed oscillation spectra comprising individual frequencies for numerous solar-type stars and red giants are or will become available. These data can lead to a precise…
Comprehensive stellar seismic analysis: A preliminary application of Whosglad to 16 Cygni system
M. Farnir, M-A. Dupret, S. J. A. J. Salmon +2
We present a first application of Whosglad method to the components A and B of the 16 Cygni system. The method was developed to provide a comprehensive analysis of stellar oscillat…
Constraining convective regions with asteroseismic linear structural inversions
G. Buldgen, D. R. Reese, M. A. Dupret
Context. Convective regions in stellar models are always associated with uncertainties, for example due to extra-mixing or the possible inaccurate position of the transition from c…
Revisiting Kepler-444 Part I. Seismic modelling and inversions of stellar structure
G. Buldgen, M. Farnir, C. Pezzotti +10
Context. The CoRoT and Kepler missions have paved the way for synergies between exoplanetology and asteroseismology. The use of seismic data helps providing stringent constraints o…
Investigating the impact of Solar Fusion III reaction rates on helioseismic constraints and solar neutrino fluxes
T. Sandron, G. Buldgen, A. Noels +2
Nuclear reaction rates are crucial ingredients of solar and stellar models, they directly impact the duration of the life of stars and the energy they produce. In the solar case, t…
Asteroseismology of evolved stars to constrain the internal transport of angular momentum. V. Efficiency of the transport on the red giant branch and in the red clump
F. D. Moyano, P. Eggenberger, G. Meynet +4
Thanks to asteroseismology, constraints on the core rotation rate are available for hundreds of low- and intermediate-mass stars in evolved phases. Current physical processes teste…
Characterizing six seismic solar analogs observed by Kepler, K2, and HERMES
R. A. GarcÃa, S. Mathur, G. T. Hookway +31
Solar analogs, stars that closely match the fundamental properties of the Sun, provide key benchmarks for testing stellar structure and evolution across different ages and activity…
Heavy Elements Abundances Inferred from the First Adiabatic Exponent in the Solar Envelope
V. A. Baturin, A. V. Oreshina, G. Buldgen +5
The first adiabatic exponent profile, noted , computed along adiabatic coordinates is in the focus of our study. Under conditions of almost fully ionized hydrogen a…
Kepler-93: a testbed for detailed seismic modelling and orbital evolution of super-earths around solar-like stars
J. Bétrisey, C. Pezzotti, G. Buldgen +4
The advent of space-based photometry missions such as CoRoT, Kepler and TESS has sparkled the development of asteroseismology and exoplanetology. The advent of PLATO will further s…
The age of the Methuselah star in light of stellar evolution models with tailored abundances
C. Guillaume, G. Buldgen, A. M. Amarsi +5
Context. HD140283, or the Methuselah star, is a well-known reference object in stellar evolution. Its peculiar chemical composition, proximity and absence of reddening makes it an…
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…
The internal rotation of low-mass stars from solar and stellar seismology
G. Buldgen, P. Eggenberger
The possibility of measuring the internal rotation of the Sun and stars thanks to helio- and asteroseismology offers tremendous constraints on hydro- and magnetohydrodynamical proc…
Rotation rate of the solar core as a key constraint to magnetic angular momentum transport in stellar interiors
P. Eggenberger, G. Buldgen, S. J. A. J Salmon
Context: The internal rotation of the Sun constitutes a fundamental constraint when modelling angular momentum transport in stellar interiors. In addition to the more external regi…
The key impact of the host star's rotational history on the evolution of TOI-849b
C. Pezzotti, O. Attia, P. Eggenberger +2
TOI-849b is one of the few planets populating the hot-Neptune desert and it is the densest Neptune-sized one discovered so far. Its extraordinary proximity to the host star, togeth…
Current problems in stellar evolution
G. Buldgen
The theory of stellar evolution plays a central role in astrophysics as stellar models are used to infer properties for Galactic and Extragalactic stellar populations as well as ex…
Entropy proxy inversions as tracers of the evolution of physical conditions at the base of the solar convective envelope
G. Buldgen, A. Noels, V. A. Baturin +4
The Sun is an important calibrator for the theory of stellar structure and evolution. However, the accuracy of our solar evolution models is tightly linked to the physical ingredie…
In-depth study of 16CygB using inversion techniques
G. Buldgen, S. J. A. S. Salmon, D. R. Reese +1
The 16Cyg binary system hosts the solar-like Kepler targets with the most stringent observational constraints. Moreover, this system is particularly interesting since both stars ar…
Detailed theoretical analysis of core Helium-burning stars: Mixed mode patterns I. Impact of the He-flash discontinuity and of induced semi-convection
L. Panier, G. Buldgen, M. Matteuzzi +4
Space missions like CoRoT, Kepler, and TESS have made asteroseismology a powerful probe of stellar interiors. Red giants are key targets thanks to their rich mixed-mode oscillation…
Advancing accuracy in age determinations of old-disk stars using an oscillating red giant in an eclipsing binary
J. S. Thomsen, A. Miglio, K. Brogaard +26
The study of resonant oscillation modes in low-mass red giant branch stars enables their ages to be inferred with exceptional (10%) precision, unlocking the possibility to re…
Combining multiple structural inversions to constrain the Solar modelling problem
G. Buldgen, S. J. A. J. Salmon, A. Noels +4
The Sun is the most studied of stars and a laboratory of fundamental physics. However, the understanding of our star is stained by the solar modelling problem which can stem from v…
Asteroseismic modelling of Kepler Legacy stars including lithium depletion
G. Buldgen, J. Bétrisey, C. Pezzotti +2
Context. The Kepler Legacy sample is, to this day, the sample of solar-like oscillators with the most exquisite asteroseismic data. In this work, we carry out a detailed modelling…
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…
Is planetary inward migration responsible for GJ 504's fast rotation and bright X-ray luminosity? New constraints from eROSITA
C. Pezzotti, G. Buldgen, E. Magaudda +4
The discovery of an increasing variety of exoplanets in very close orbits around their host stars raised many questions about how stars and planets interact, and to which extent ho…
Probing stellar cores from inversions of frequency separation ratios
J. Bétrisey, G. Buldgen
With the rapid development of asteroseismology thanks to space-based photometry missions such as CoRoT, Kepler, TESS, and in the future, PLATO, and the use of inversion techniques,…
The solar beryllium abundance revisited with 3D non-LTE models
A. M. Amarsi, D. Ogneva, G. Buldgen +3
The present-day abundance of beryllium in the solar atmosphere provides clues about mixing mechanisms within stellar interiors. However, abundance determinations based on the Be II…
Coralie radial velocity search for companions around evolved stars (CASCADES) II. Seismic masses for three red giants orbited by long-period massive planets
G. Buldgen, G. Ottoni, C. Pezzotti +10
The advent of asteroseismology as the golden path to precisely characterize single stars naturally led to synergies with the field of exoplanetology. Today, the precise determinati…
Higher metal abundances do not solve the solar problem
G. Buldgen, P. Eggenberger, A. Noels +4
Context. The Sun acts as a cornerstone of stellar physics. Thanks to spectroscopic, helioseismic and neutrino flux observations, we can use the Sun as a laboratory of fundamental p…
Progress in global helioseismology: a new light on the solar modelling problem and its implications for solar-like stars
G. Buldgen, A. Noels, S. Salmon
Since the first observations of solar oscillations, helioseismology has been one of the most successful fields of astrophysics. Data of high quality were obtained through the imple…
The evolution and impact of 3000 M stars in the early Universe
D. Nandal, E. Farrell, G. Buldgen +2
We present evolutionary models of massive, accreting population III stars with constant and variable accretion rates until the end of silicon burning, with final masses of 1000 - 3…
In-depth analysis of solar models with high-metallicity abundances and updated opacity tables
G. Buldgen, A. Noels, R. Scuflaire +10
Due to the high quality constraints available for the Sun, we can carry out combined analyses using neutrino, spectroscopic and helioseismic observations. Such studies lay the grou…
From the Sun to solar-like stars: how does the solar modelling problem affect our studies of solar-like oscillators?
G. Buldgen, C. Pezzotti, M. Farnir +2
Since the first observations of solar oscillations in 1962, helioseismology has probably been one of the most successful fields of astrophysics. Besides the improvement of observat…
Constraints on planetary tidal dissipation from a detailed study of Kepler 91b
L. Fellay, C. Pezzotti, G. Buldgen +2
Context. With the detection of thousands of exoplanets, characterising their dynamical evolution in detail represents a key step in the understanding of their formation. Studying t…
Comprehensive stellar seismic analysis : New method exploiting the glitches information in solar-like pulsators
M. Farnir, M-A. Dupret, S. J. A. J. Salmon +2
Aims: We develop a method that provides a comprehensive analysis of the oscillation spectra of solar-like pulsators. We define new seismic indicators that should be as uncorrelated…
A data-driven estimate of the protosolar helium mass fraction
G. Buldgen, M. Kunitomo, A. Noels +3
The protosolar helium mass-fraction is a key ingredient of solar, planetary models and enrichment laws. However, the assumed values often rely on simplified descriptions of the tra…
The stellar activity-rotation-age relationship under the lens of asteroseismology
C. Pezzotti, J. Bétrisey, G. Buldgen +6
In low-mass stars, the connection between magnetic activity, rotation period, and age provides key insights into the functioning of dynamos. Fully understanding the activity-rotati…
Helioseismic determination of the solar metal mass fraction
G. Buldgen, A. Noels, V. A. Baturin +5
Context. The metal mass fraction of the Sun Z is a key constraint in solar modelling, but its value is still under debate. The standard solar chemical composition of the late 2000s…
Revisiting Kepler-444. II. Rotational, orbital and high-energy fluxes evolution of the system
C. Pezzotti, P. Eggenberger, G. Buldgen +3
Context. Kepler-444 is one of the oldest planetary systems known thus far. Its peculiar configuration consisting of five sub-Earth-sized planets orbiting the companion to a binary…
Amplitude of solar gravity modes generated by penetrative plumes
C. Pinçon, T. Appourchaux, G. Buldgen
The detection of gravity modes is expected to give us unprecedented insights into the inner dynamics of the Sun. Within this framework, predicting their amplitudes is essential to…
Eating planets makes you younger: The magnetic dynamo rejuvenation of GJ 504 by planetary engulfment
S. Bellotti, C. Pezzotti, G. Buldgen +3
With the discovery of a few thousand exoplanets, questions have been raised regarding star-planet interactions and whether the presence of a companion may affect stellar properties…
Asteroseismic investigation of HD 140283: The Methuselah star
M. S. Lundkvist, J. R. Larsen, Y. Li +12
HD 140283 is a well-studied metal-poor subgiant and a Gaia benchmark star, often used for testing stellar models due to its proximity, brightness, and low metallicity ([Fe/H] = -2.…
Global Helioseismology
G. Buldgen
Helioseismology is one of the most successful fields of astrophysics. The observation and characterization of solar oscillation has allowed solar seismologists to study the interna…
Thorough characterisation of the 16 Cygni system Part I: Forward seismic modelling with WhoSGlAd
M. Farnir, M. -A. Dupret, G. Buldgen +5
Context: Being part of the brightest solar-like stars, and close solar analogues, the 16 Cygni system is of great interest to the scientific community and may provide insight into…
Seismic inversion of the solar entropy: A case for improving the Standard Solar Model
G. Buldgen, S. J. A. J. Salmon, A. Noels +9
The Sun is the most constrained and well-studied of all stars. As a consequence, the physical ingredients entering solar models are used as a reference to study all other stars obs…
AIMS - A new tool for stellar parameter determinations using asteroseismic constraints
B. M. Rendle, G. Buldgen, A. Miglio +12
A key aspect in the determination of stellar properties is the comparison of observational constraints with predictions from stellar models. Asteroseismic Inference on a Massive Sc…
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…
Using seismic inversions to obtain an internal mixing processes indicator for main-sequence solar-like stars
G. Buldgen, D. R. Reese, M. A. Dupret
Determining accurate and precise stellar ages is a major problem in astrophysics. These determinations are either obtained through empirical relations or model-dependent approaches…