A5035528628- Stellar, planetary, and galactic studies
- Astro and Planetary Science
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Spacecraft Design and Technology
- Geophysics and Gravity Measurements
- Astronomical Observations and Instrumentation
- Distributed and Parallel Computing Systems
- Pulsars and Gravitational Waves Research
- Geophysics and Sensor Technology
- Atomic and Molecular Physics
- Scientific Research and Discoveries
- Tropical and Extratropical Cyclones Research
- Laser-induced spectroscopy and plasma
- History and Developments in Astronomy
- Wind and Air Flow Studies
- Inertial Sensor and Navigation
- Gamma-ray bursts and supernovae
- High-pressure geophysics and materials
- Adaptive optics and wavefront sensing
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2012-2024
Université Paris Sciences et Lettres
2014-2024
Université de Versailles Saint-Quentin-en-Yvelines
2009-2024
Sorbonne Université
2009-2024
Université Paris Cité
2011-2024
Observatoire de Paris
2003-2024
Centre National de la Recherche Scientifique
2009-2024
Délégation Paris 7
2012-2021
Janssen (France)
2005-2019
Janssen (Belgium)
2009
PLAnetary Transits and Oscillations of stars (PLATO) is an ESA M-class mission to be launched by the end 2026 discover characterize transiting planets around bright nearby stars, in particular habitable rocky hosted solar-like stars. Over lifetime, average 8% science data rate will allocated Guest Observer programs selected through public calls. Hence, it essential for community know advance where observing fields located. In a previous paper, we identified two preliminary long-pointing...
Aims. In this work, we determine the expected yield of detections solar-like oscillations for targets foreseen PLATO ESA mission. Our estimates are based on a study detection probability, which takes into account properties target stars, using information available in PIC 1.1.0, including current best estimate signal-to-noise ratio (S/N). The stellar samples, as defined mission, include those with lowest noise level (P1 and P2 samples) P5 sample, has higher level. For P1 S/N is high enough...
PLATO (PLAnetary Transits and Oscillations of stars) is an ESA M-class satellite planned for launch by end 2026 dedicated to the wide-field search transiting planets around bright nearby stars, with a strong focus on discovering habitable rocky hosted solar-like stars. The choice fields be pointed at crucial task since it has direct impact scientific return mission. In this paper we describe discuss formal requirements key prioritization criteria that have taken into account in Long-duration...
Helioseismology and asteroseismology of red giant stars have shown that the distribution angular momentum in stellar interiors, its evolution with time remains an open issue physics. Owing to unprecedented quality Kepler photometry, we are able seismically infer internal rotation rates \gamma Doradus stars, which provide MS counterpart red-giants puzzle. We confront these models rotationally induced transport momentum, order test mechanisms. used a model-independent method developed by...
Context. Seismic observations with the space-borne Kepler mission have shown that a number of evolved stars exhibit low-amplitude dipole modes, which is referred to as depressed modes. Recently, these low amplitudes been attributed presence strong magnetic field in stellar core those stars. Subsequently, and based on this scenario, prevalence high fields has inferred. It should be noted, however, conclusion remains indirect. Aims. We intend study properties mode depression stars, necessary...
PLAnetary Transits and Oscillations of stars (PLATO) is an ESA M-class mission to be launched by the end 2026 discover characterize transiting planets around bright nearby stars, in particular habitable rocky hosted solar-like stars. Over lifetime, average 8% science data rate will allocated Guest Observer programs (GOs) selected through public calls, hence it essential for community know advance where observing fields located. In a previous paper, we identified two preliminary long-pointing...
The CoRoT and Kepler missions provided a wealth of high-quality data for solar-like oscillations. To make the best such seismic inferences, we need theoretical models with precise near-surface structure, which has significant influence on oscillation frequencies. mixing-length parameter, $\alpha$, is key factor structure. In convection formulations used in evolution codes, $\alpha$ free parameter that needs to be properly specified. We calibrated values by matching entropy profiles 1D...
A growing number of solar-like oscillations has been detected in red giant stars thanks to CoRoT and Kepler space-crafts. The seismic data gathered by on allow us test mode driving theory physical conditions different from main-sequence stars. Using a set 3D hydrodynamical models representative the upper layers sub- stars, we computed acoustic energy supply rate (Pmax). Assuming adiabatic pulsations using global stellar that assume surface stratification comes models, amplitude terms...
From different seismic observations we infer the energy supplied per unit of time by turbulent convection to acoustic modes α Centauri A (HD 128620), a star that is similar but not identical Sun. The inferred rates (i.e. mode excitation rates) are found be significantly higher than in They compared with those computed an model includes two sources driving, Reynolds stress contribution and advection entropy fluctuations. also uses closure model, Closure Model Plumes (CMP hereafter), takes...
The space missions CoRoT and Kepler provide high quality data that allow us to test the transport of angular momentum in stars by seismic determination internal rotation profile. Our aim is validity diagnostics for red giants are based on a perturbative method investigate oscillation spectra when does not hold. We use non-perturbative approach implemented ACOR code (Ouazzani et al. 2012) accounts effect pulsations, solves pulsation eigenproblem directly dipolar modes. find limit perturbation...
Asteroseismology is a unique tool that can be used to study the interior of stars and hence deliver information for studiy stellar physics, evolution, Galactic archaeology. We aim develop simple model content asteroseismology characterize ability precision with which fundamental properties estimated different space missions. defined calibrated metrics seismic performance. The metrics, expressed by index ${\mathcal{E}$ scaling relations, are calculated an ensemble stars. studied relations...
Context. Modeling the convection process is a long-standing problem in stellar physics. To date, all ad hoc models have relied on free parameter, α , (among others) that has no real physical justification and therefore poorly constrained. However, link exists between this parameter entropy of adiabat. There are existing prescriptions, derived from 3D atmospheric models, treat as function parameters (effective temperature, surface gravity, chemical composition). This can offer sufficient...
From the seismic data obtained by CoRoT for star HD 49933 it is possible, as Sun, to constrain models of excitation acoustic modes turbulent convection. We compare a stochastic model described in Paper I (arXiv:0910.4027) with asteroseismology 49933, that rather metal poor and significantly hotter than Sun. Using mode linewidths measured theoretical rates computed I, we derive expected surface velocity amplitudes detected 49933. calibrated quasi-adiabatic approximation relating intensity...
The GIII red giant star <i>ϵ<i/> Oph has been found to exhibit several modes of oscillation by the MOST mission. We interpret observed frequencies in terms theoretical radial <i>p<i/>-mode stellar models. Evolutionary models this star, both shell H-burning and core He-burning phases evolution, are constructed using as constraints a combination measurements from classical ground-based observations (for luminosity, temperature, chemical composition) seismic MOST. Radial either evolutionary...
By pursuing the goal to find new variables in COROT field–of–view we characterised a sample of stars located lower part instability strip. Our is composed belonging disk population solar neighbourhood. We found that 23% display multiperiodic light variability up few mmag amplitude, i.e., easily detectable on single night photometry. photometry fixed most middle strip and high–resolution spectroscopy established they have km s-1. An analysis Rodriguez & Breger ([CITE]) (δ Sct whole Galaxy)...
(abridged) Recent work on several beta Cephei stars has succeeded in constraining both their interior rotation profile and convective core overshoot. In particular, a recent study focusing theta$ Oph shown that overshoot parameter of alpha = 0.44 is required to model the observed pulsation frequencies, significantly higher than for other this type. We investigate effects early type main sequence pulsators, attempt use low order frequencies constrain these parameters. This will be applied few...
SOURCE (OR PART OF THE FOLLOWING SOURCE): Type article Title Amplitudes and lifetimes of solar-like oscillations observed by CoRoT: redgiant versus main-sequence stars. (Corrigendum) Author(s) F. Baudin, C. Barban, K. Belkacem, S. Hekker, T. Morel, R. Samadi, O. Benomar, M.J. Goupil, Carrier, J. Ballot, Deheuvels, de Ridder, et al. Faculty FNWI: Astronomical Institute Anton Pannekoek (IAP) Year 2011
Information about the rotation rate is contained in low frequency part of power spectra, where signatures nonuniform surface are expected, as well splittings induced by internal rate. We wish to figure out whether differences between seismic period determined a mean rotational splitting, and measured from peak Fourier spectrum (observed for some CoRoT's targets) can provide constraints on profile. For uniform moderate rotators,perturbative corrections second third order terms angular...