A5072048177- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Solar and Space Plasma Dynamics
- Astrophysics and Star Formation Studies
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
- Geomagnetism and Paleomagnetism Studies
- Inertial Sensor and Navigation
- Space Exploration and Technology
- Planetary Science and Exploration
- Geophysics and Sensor Technology
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- Calibration and Measurement Techniques
- Advanced Thermodynamic Systems and Engines
Institute of Science and Technology Austria
2023-2024
Université Paris Cité
2018-2022
Astrophysique, Instrumentation et Modélisation
2018-2022
Centre National de la Recherche Scientifique
2018-2022
Simons Foundation
2021-2022
Sorbonne Paris Cité
2018-2022
Université Paris-Saclay
2018-2022
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2018-2022
CEA Paris-Saclay
2018-2022
Délégation Paris 7
2018-2022
We report on the confirmation and mass determination of Pi Men c, first transiting planet discovered by NASA's TESS space mission. is a naked-eye (V=5.65 mag), quiet G0 V star that was previously known to host sub-stellar companion (Pi b) long-period (Porb = 2091 days), eccentric (e 0.64) orbit. Using time-series photometry, combined with Gaia data, published UCLES@AAT Doppler measurements, archival HARPS@ESO-3.6m radial velocities, we found c close-in an orbital period Porb 6.27 days, Mc...
We present the discovery of TOI-197.01, first transiting planet identified by Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology host star is possible. TOI-197 (HIP116158) a bright (V=8.2 mag), spectroscopically classified subgiant oscillates with an average frequency about 430 muHz and displays clear signature mixed modes. The oscillation amplitude confirms that redder TESS bandpass compared to Kepler has small effect on oscillations, supporting expected yield thousands...
Abstract In the third APOKASC catalog, we present data for complete sample of 15,808 evolved stars with APOGEE spectroscopic parameters and Kepler asteroseismology. We used 10 independent asteroseismic analysis techniques anchor our system on fundamental radii derived from Gaia L T eff . provide evolutionary state, surface gravity, mass, radius, age, to derive them 12,418 stars. This includes 10,036 exceptionally precise measurements, median fractional uncertainties in <mml:math...
We present the third and final data release of K2 Galactic Archaeology Program (K2 GAP) for Campaigns C1-C8 C10-C18. provide asteroseismic radius mass coefficients, $\kappa_R$ $\kappa_M$, $\sim 19,000$ red giant stars, which translate directly to given a temperature. As such, GAP DR3 represents largest sample in literature date. stellar parameters are calibrated be on an absolute parallactic scale based Gaia DR2, with branch clump evolutionary state classifications provided via...
Since the onset of `space revolution' high-precision high-cadence photometry, asteroseismology has been demonstrated as a powerful tool for informing Galactic archaeology investigations. The launch NASA TESS mission enabled seismic-based inferences to go full sky -- providing clear advantage large ensemble studies different Milky Way components. Here we demonstrate its potential investigating Galaxy by carrying out first asteroseismic study red giant stars observed TESS. We use sample 25...
Over 2,000 stars were observed for one month with a high enough cadence in order to look acoustic modes during the survey phase of \kep\ mission. Solar-like oscillations have been detected about 540 stars. The question why no remaining is still open. Previous works explained non-detection level magnetic activity However, sample studied contained some classical pulsators and red giants that could biased results. In this work, we revisit analysis on cleaner main-sequence solar-like consists...
Context. The discovery of moderate differential rotation between the core and envelope evolved solar-like stars could be signature a strong magnetic field trapped inside radiative interior. population intermediate-mass red giants presenting surprisingly low-amplitude mixed modes (i.e. oscillation that behave as acoustic in their external gravity core) also arise from effect an internal field. Indeed, more massive than about 1.1 solar masses are known to develop convective during main...
Abstract The ages of solar-like stars have been at the center many studies such as exoplanet characterization or Galactic-archeology. While are usually computed from stellar evolution models, relations linking to other properties, rotation and magnetic activity, investigated. With large catalog 55,232 periods, P rot , photometric activity index, S ph Kepler data, we opportunity look for magneto-gyro-chronology relations. Stellar obtained with two codes that include treatment angular momentum...
Our knowledge of the dynamics stars has undergone a revolution thanks to simultaneous large amount high-quality photometric observations collected by space-based asteroseismology and ground-based high-precision spectropolarimetry. They allowed us probe internal rotation their surface magnetism in whole Hertzsprung-Russell diagram. However, new methods should still be developed deep magnetic fields those stars. goal is provide seismic diagnoses that allow sound Here, we focus on asymptotic...
Space asteroseismology is revolutionizing our knowledge of the internal structure and dynamics stars. A breakthrough ongoing with recent discoveries signatures strong magnetic fields in core red giant The key signature for such a detection asymmetry these induce frequency splittings observed dipolar mixed gravito-acoustic modes. We investigate ability asymmetries modes to constrain geometrical properties deep fields. use powerful analytical Racah-Wigner algebra used Quantum Mechanics...
The presence of dips in the gravity mode period spacing versus diagram γ Doradus stars is now well established thanks to recent asteroseismic studies. Such Lorentzian-shaped inertial arise from interaction gravito-inertial modes radiative envelope intermediate-mass main sequence with pure their convective core, and allow us study stellar internal properties. This window onto dynamics extremely valuable context understanding angular-momentum transport inside stars, as it allows probe rotation...
Recent observational results from asteroseismic studies show that an important fraction of solar-like stars do not present detectable stochastically excited acoustic oscillations. This non-detectability seems to correlate with a high rotation rate in the convective envelope and surface magnetic activity. At same time, properties stellar convection are affected by magnetism. We investigate role excitation modes stars, evaluate its impact on energy injected derived theoretical prescriptions...
The recently published Kepler mission Data Release 25 (DR25) reported on ~197,000 targets observed during the mission. Despite this, no wide search for red giants showing solar-like oscillations have been made across all stars in Kepler's long-cadence mode. In this work, we perform task using custom apertures pixel files and detect 21,914 stars, representing largest sample of oscillating to date. We measure their frequency at maximum power, $ν_{\mathrm{max}}$, down...
Brightness variations due to dark spots on the stellar surface encode information about rotation and magnetic activity. In this work, we analyze Kepler long-cadence data of 26,521 main-sequence stars spectral types M K in order measure their photometric activity level. Rotation-period estimates are obtained by combination a wavelet analysis autocorrelation function light curves. Reliable determined comparing results from different diagnostics four sets. We also proxy using amplitude flux an...
In order to understand stellar evolution, it is crucial efficiently determine surface rotation periods. An efficient tool automatically reliable periods needed when dealing with large samples of photometric datasets. The objective this work develop such a tool. Random forest learning abilities are exploited automate the extraction in Kepler light curves. Rotation and complementary parameters obtained from three different methods: wavelet analysis, autocorrelation function curve, composite...
The Planetary Transits and Oscillations of stars mission (PLATO) will allow us to measure surface rotation monitor photometric activity tens thousands main sequence solar-type subgiant stars. This paper is the first a series dedicated preparation analysis stellar photospheric with near-future PLATO data. We describe in this work strategy that be implemented pipeline rotation, activity, long-term modulations. algorithms are applied on both noise-free noisy simulations stars, which include...
ABSTRACT Red giant stars host solar-like oscillations which have mixed character, being sensitive to conditions both in the outer convection zone and deep within interior. The properties of these modes are core rotation magnetic fields. While asteroseismic studies former been done on a large scale, latter currently limited tens stars. We aim produce first catalogue rotational perturbations. jointly constrain parameters by devising an automated method for fitting power spectra directly....
We report the discovery and characterization of HD 89345b (K2-234b; EPIC 248777106b), a Saturn-sized planet orbiting slightly evolved star. 89345 is bright star ($V = 9.3$ mag) observed by K2 mission with one-minute time sampling. It exhibits solar-like oscillations. conducted asteroseismology to determine parameters star, finding mass radius be $1.12^{+0.04}_{-0.01}~M_\odot$ $1.657^{+0.020}_{-0.004}~R_\odot$, respectively. The appears have recently left main sequence, based on inferred age,...
Asteroseismology provides global stellar parameters such as masses, radii, or surface gravities using mean seismic and effective temperature for thousands of low-mass stars (0.8 M ⊙ < 3 ). This methodology has been successfully applied to in which acoustic modes excited by turbulent convection are measured. Other methods the Flicker technique can also be used determine gravities, but only works log g above 2.5 dex. In this work, we present a new metric called FliPer (Flicker spectral...
Abstract Studies of Galactic structure and evolution have benefited enormously from Gaia kinematic information, though additional, intrinsic stellar parameters like age are required to best constrain models. Asteroseismology is the most precise method providing such information for field star populations en masse, but existing samples part been limited a few narrow fields view by CoRoT Kepler missions. In an effort provide well-characterized across wide range in position, we present second...
During the survey phase of Kepler mission, several thousands stars were observed in short cadence, allowing detection solar-like oscillations more than 500 main-sequence and sub-giant stars. Later, Science Office discovered an issue calibration that affected half short-cadence data, leading to a new data release (DR25) with improved corrections. We re-analyze one-month time series search for oscillations. study seismic parameters 99 (46 targets reported oscillations) increasing by around 8%...
The NASA Transiting Exoplanet Survey Satellite (TESS) is observing tens of millions stars with time spans ranging from $\sim$ 27 days to about 1 year continuous observations. This vast amount data contains a wealth information for variability, exoplanet, and stellar astrophysics studies but requires number processing steps before it can be fully utilized. In order efficiently process all the TESS make available wider scientific community, Data Asteroseismology working group, as part...