A5074838508- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Adaptive optics and wavefront sensing
- Solar and Space Plasma Dynamics
- Spectroscopy and Laser Applications
- High-pressure geophysics and materials
- Spacecraft Design and Technology
- Astrophysical Phenomena and Observations
- Geophysics and Gravity Measurements
- Galaxies: Formation, Evolution, Phenomena
- Advanced Mathematical Theories and Applications
- Atmospheric Ozone and Climate
- Cybersecurity and Information Systems
- Oceanographic and Atmospheric Processes
- History and Developments in Astronomy
- Advanced Measurement and Metrology Techniques
- Inertial Sensor and Navigation
- Geophysics and Sensor Technology
- Pulsars and Gravitational Waves Research
- Calibration and Measurement Techniques
- CCD and CMOS Imaging Sensors
Institute of Astronomy
2016-2024
KU Leuven
2015-2024
VIB-KU Leuven Center for Microbiology
2020-2022
Villanova University
2020
Max Planck Institute for Astronomy
2019
Max Planck Society
2019
Thüringer Landessternwarte Tautenburg
2008-2011
Galaxies, Etoiles, Physique et Instrumentation
2010
Yandex (Russia)
2007
Context. Gamma Doradus stars (hereafter γ Dor stars) are known to exhibit gravity- and/or gravito-intertial modes that probe the inner stellar region near convective core boundary. The non-equidistant spacing of pulsation periods is an observational signature evolutions and current internal structure heavily influenced by rotation.
SDSS-V will be an all-sky, multi-epoch spectroscopic survey of over six million objects. It is designed to decode the history Milky Way, trace emergence chemical elements, reveal inner workings stars, and investigate origin planets. also create integral-field map gas in Galaxy Local Group that 1,000x larger than current state art at high enough spatial resolution self-regulation mechanisms galactic ecosystems. pioneer systematic, monitoring across whole sky, revealing changes on timescales...
The Kepler spacecraft is providing time series of photometric data with micromagnitude precision for hundreds A-F type stars. We present a first general characterization the pulsational behaviour stars as observed in light curves sample 750 candidate propose three main groups to describe variety pulsating stars: gamma Dor, delta Sct, and hybrid assign 63% our one groups, identify remaining part rotationally modulated/active stars, binaries, different spectral type, or that show no clear...
Gamma Doradus stars (hereafter γ Dor stars) are gravity-mode pulsators of spectral type A or F. Such modes probe the deep stellar interior, offering a detailed fingerprint their structure. Four-year high-precision space-based Kepler photometry has become available, allowing us to study these with unprecedented detail. We selected, analyzed, and characterized sample 67 for which we have observations available. For all targets in assembled high-resolution spectroscopy confirm F-type nature....
The unparalleled photometric data obtained by NASA's Kepler space telescope led to an improved understanding of red giant stars and binary stars. Seismology allows us constrain the properties giants. In addition eclipsing binaries, eccentric non-eclipsing exhibiting ellipsoidal modulations, have been detected with Kepler. We aim study systems containing a star derive parameters primary component. apply asteroseismic techniques determine masses radii component each system. For selected...
Context. OB stars are important building blocks of the Universe, but we have only a limited sample them well understood enough from an asteroseismological point view to provide feedback on current evolutionary models. Our study adds one special case this sample, with more observational constraints than for most these stars. Aims. goal is analyse and interpret pulsational behaviour B3 IV star HD 43317 using CoRoT light curve along ground-based spectroscopy gathered by Harps instrument. This...
Abstract We propose a methodological framework to perform forward asteroseismic modeling of stars with convective core, based on gravity-mode oscillations. These probe the near-core region in deep stellar interior. The relies set observed high-precision oscillation frequencies low-degree coherent gravity modes long lifetimes and their observational uncertainties. Identification mode degree azimuthal order is assumed be achieved from rotational splitting and/or period spacing patterns. This...
Abstract The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is a dual-hemisphere, near-infrared (NIR), spectroscopic survey with the goal of producing chemodynamical mapping Milky Way. targeting for APOGEE-2 complex and has evolved time. In this paper, we present updates additions to initial strategy APOGEE-2N presented in Zasowski et al. (2017). These modifications come two implementation modes: (i) “Ancillary Science Programs” competitively awarded Sloan Digital Sky...
APOGEE is a high-resolution (R sim 22,000), near-infrared, multi-epoch, spectroscopic survey of the Milky Way. The second generation project, APOGEE-2, includes an expansion to Southern Hemisphere called APOGEE-2S. This enabled perform fully panoramic mapping all main regions Way; in particular, by operating H-band, uniquely able probe dust-hidden inner Way that are best accessed from Hemisphere. In this paper we present targeting strategy APOGEE-2S, with special attention documenting...
We set out to determine stellar labels from low-resolution survey spectra of hot, OBA stars with effective temperature (Teff) higher than 7500K. This fills a gap in the scientific analysis large spectroscopic surveys such as LAMOST, which offers for millions at R=1800. first explore theoretical information content determining labels, via Cram\'er-Rao bound. show that limit perfect model and observed S/N 100, precise estimates are possible wide range labels: not only Teff, surface gravity...
With the PLAnetary Transits and Oscillation of stars (PLATO) space mission set for launch in December 2026 by European Space Agency (ESA), a new photometric legacy future scientific discoveries await community. By exploring topics outside core science program, PLATO complementary program (PLATO-CS) provides unique opportunity to maximise yield mission. In this work, we investigate PLATO’s potential observing pulsating across Hertzsprung--Russell diagram (HRD). This search is distinct from...
Hierarchical triple systems comprise a close binary and more distant component. They are important for testing theories of star formation stellar evolution in the presence nearby companions. We obtained 218 days Kepler photometry HD 181068 (magnitude 7.1), supplemented by groundbased spectroscopy interferometry, which show it to be hierarchical with two types mutual eclipses. The primary is red giant that 45-day orbit pair dwarfs 0.9-day orbit. shows evidence tidally-induced oscillations...
Massive stars are important building blocks of the Universe, and their stellar structure evolution models fundamental cornerstones various fields in modern astrophysics. The precision these is limited by our lack understanding internal mixing processes that significantly influence lifetime objects (e.g. core overshoot, chemical mixing, or differential rotation). Our goal to calibrate extending sample available seismic studies slowly pulsating B (SPB) stars, providing input for theoretical...
ABSTRACT We study the dynamics of stellar interior early red-giant star KIC 4448777 by asteroseismic inversion 14 splittings dipole mixed modes obtained from Kepler observations. In order to overcome complexity oscillation pattern typical stars, we present a procedure extract rotational power spectrum. find not only that core rotates minimum 8 maximum 17 times faster than surface, confirming previous results generated for other red giants (Deheuvels et al.), but also estimate variation...
Context. The analysis of stellar oscillations is one the most reliable ways to probe interiors. Recent space missions such as Kepler have provided us with an opportunity study these unprecedented detail. For many multi-periodic pulsators γ Doradus stars, this led detection dozens hundreds oscillation frequencies that could not be found from ground-based observations. Aims. We aim detect non-uniform period spacings in Fourier spectra a sample stars observed by Kepler. Such complicated both...
The asteroseismic modelling of period spacing patterns from gravito-inertial modes in stars with a convective core is high-dimensional problem. We utilise the measured pattern prograde dipole gravity (acquiring $\Pi_0$), combination effective temperature ($T_{\rm eff}$) and surface ($\log g$) derived spectroscopy, to estimate fundamental stellar parameters properties 37 $\gamma~$Doradus ($\gamma~$Dor) whose rotation frequency has been $\textit{Kepler}$ photometry. make use two 6D grids...
Context. Main sequence stars with a convective core are predicted to stochastically excite Internal Gravity Waves (IGWs), which effectively transport angular momentum throughout the stellar interior and explain observed near-uniform rotation rates of intermediate-mass stars. However, there few detections IGWs, fewer still made using photometry, more needed constrain numerical simulations. Aims. We aim formalise detection characterisation IGWs in photometric observations born cores (M > 1.5...
We present a detailed analysis and interpretation of the high-mass binary V380 Cyg, based on high-precision space photometry gathered with Kepler mission as well high-resolution ground-based spectroscopy obtained HERMES spectrograph attached to 1.2m Mercator telescope. derive precise orbital solution full physical properties system, including dynamical component mass estimates 11.43+/-0.19 7.00+/-0.14 solar masses for primary secondary, respectively. Our frequency reveals rotation in both...
We present the first results from Transiting Exoplanet Survey Satellite (TESS) on rotational and pulsational variability of magnetic chemically peculiar A-type stars. analyse TESS 2-min cadence data sectors 1 2 a sample 83 Five new rapidly oscillating Ap (roAp) stars are announced. One these pulsates with periods around 4.7 min, making it shortest period roAp star known to date. Four out five multiperiodic. Three singly periodic one show presence mode splitting. Individual frequencies...
The space-missions MOST, CoRoT, and Kepler deliver a huge amount of high-quality photometric data suitable to study numerous pulsating stars. Our ultimate goal is detection analysis an extended sample Gamma Dor-type stars with the aim search for observational evidence non-uniform period spacings rotational splittings gravity modes in main-sequence typically twice as massive Sun. We applied automated supervised classification method select 69 Doradus candidate used advanced extract light...
We present the first detection of a rotationally affected series consisting 36 consecutive high-order sectoral dipole gravity modes in slowly pulsating B (SPB) star. The results are based on analysis four years virtually uninterrupted photometric data assembled with Kepler Mission, and high-resolution spectra acquired using HERMES spectrograph at 1.2 meter Mercator Telescope. spectroscopic measurements place KIC7760680 inside SPB instability strip, near cool edge. reveals longest unambiguous...
Gamma Doradus and delta Scuti pulsators cover the transition region between low mass massive main-sequence stars, as such, are critical for testing stellar models. When they reside in binary systems, we can combine two independent methods to derive information, such precise fundamental parameters aid asteroseismic modelling. In Kepler light curve of KIC10080943, clear signatures gravity- pressure-mode pulsations have been found. Ground-based spectroscopy revealed this target be a...