Publications (21)
Constraining differential rotation in gamma Doradus stars from inertial dips properties
L. Barrault, L. Bugnet, S. Mathis
The presence of dips in the gravity modes period spacing versus period diagram of gamma Doradus stars is now well established by recent asteroseismic studies. Such Lorentzian-shape…
Surface rotation and photometric activity for Kepler targets I. M and K main-sequence stars
A. R. G. Santos, R. A. GarcÃa, S. Mathur +5
Brightness variations due to dark spots on the stellar surface encode information about stellar surface rotation and magnetic activity. In this work, we analyze the Kepler long-cad…
FliPer: Checking the reliability of global seismic parameters from automatic pipelines
L. Bugnet, R. A. Garcia, G. R. Davies +2
Our understanding of stars through asteroseismic data analysis is limited by our ability to take advantage of the huge amount of observed stars provided by space missions such as C…
Magnetic signatures on mixed-mode frequencies. I. An axisymmetric fossil field inside the core of red giants
L. Bugnet, V. Prat, S. Mathis +6
The discovery of the moderate differential rotation between the core and the envelope of evolved solar-like stars could be the signature of a strong magnetic field trapped inside t…
Determining surface rotation periods of solar-like stars observed by the Kepler mission using machine learning techniques
S. N. Breton, L. Bugnet, A. R. G. Santos +4
For a solar-like star, the surface rotation evolves with time, allowing in principle to estimate the age of a star from its surface rotation period. Here we are interested in measu…
FliPer: Classifying TESS pulsating stars
L. Bugnet, R. A. GarcÃa, G. R. Davies +3
The recently launched NASA Transiting Exoplanet Survey Satellite (TESS) mission is going to collect lightcurves for a few hundred million of stars and we expect to increase the num…
Expanding stellar horizons with polarized light
J. Vandersnickt, R. Ochoa Armenta, V. Vanlaer +16
The polarization of light is a critically under-utilized, rich source of information in astronomy. For stars in particular, surface magnetism polarization that can be detected and…
Measuring stellar surface rotation and activity with the PLATO mission -- I. Strategy and application to simulated light curves
S. N. Breton, A. F Lanza, S. Messina +20
The Planetary Transits and Oscillations of stars mission (PLATO) will allow us to measure surface rotation and monitor photometric activity of tens of thousands of main sequence so…
HD 89345: a bright oscillating star hosting a transiting warm Saturn-sized planet observed by K2
V. Van Eylen, F. Dai, S. Mathur +40
We report the discovery and characterization of HD 89345b (K2-234b; EPIC 248777106b), a Saturn-sized planet orbiting a slightly evolved star. HD 89345 is a bright star ( m…
Constraining the model-based uncertainties of asteroseismic magnetic field measurements in red giants
L. Buchele, L. Bugnet, N. Muntean +1
Magnetic fields inside red giants are measured using shifts to the oscillation frequencies. However, in the asymptotic framework, converting a frequency shift into a radial magneti…
Automatic classification of K2 pulsating stars using machine learning techniques
A. Le Saux, L. Bugnet, S. Mathur +2
The second mission of the NASA Kepler satellite, K2, has collected hundreds of thousands of lightcurves for stars close to the ecliptic plane. This new sample could increase the nu…
Detections of solar-like oscillations in dwarfs and subgiants with Kepler DR25 short-cadence data
S. Mathur, R. A. GarcÃa, S. N. Breton +6
During the survey phase of the Kepler mission, several thousands of stars were observed in short cadence, allowing the detection of solar-like oscillations in more than 500 main-se…
Is a 1D perturbative method sufficient for asteroseismic modelling of Cephei pulsators? Implications for measurements of rotation and internal magnetic fields
J. S. G. Mombarg, V. Vanlaer, S. B. Das +6
Asymmetries in the observed rotational splittings of a multiplet contain information about the star's rotation profile and internal magnetic field. However, to exploit this informa…
Magnetic signatures on mixed-mode frequencies. II. Period spacings as a probe of the internal magnetism of red giants
L. Bugnet
Theoretical works have looked into the various topologies and amplitudes, as well as the stability of the magnetic field that is expected to be present in the radiative interior of…
Interior rotation modelling of the Cep pulsator HD 192575 including multiplet asymmetries
V. Vanlaer, D. M. Bowman, S. Burssens +4
Rotation plays an important role in stellar evolution. However, the mechanisms behind the transport of angular momentum in stars at various stages of their evolution are not well u…
Near-degeneracy effects in Quadrupolar Mixed Modes. From an Asymptotic Description to Data Fitting
B. Liagre, A. Desai, L. Einramhof +1
Dipolar (l=1) mixed modes revealed surprisingly weak differential rotation between the core and the envelope of evolved solar-like stars. Quadrupolar (l=2) mixed modes also contain…
Revisiting the impact of stellar magnetic activity on the detectability of solar-like oscillations by Kepler
S. Mathur, R. A. Garcia, L. Bugnet +3
Over 2,000 stars were observed for one month with a high enough cadence in order to look for acoustic modes during the survey phase of the Kepler mission. Solar-like oscillations h…
TESS's first planet: a super-Earth transiting the naked-eye star Mensae
D. Gandolfi, O. Barragan, J. Livingston +29
We report on the confirmation and mass determination of Pi Men c, the first transiting planet discovered by NASA's TESS space mission. Pi Men is a naked-eye (V=5.65 mag), quiet G0…
FliPer: In search of solar-like pulsators among TESS targets
L. Bugnet, R. A. GarcÃa, S. Mathur +4
The NASA's Transiting Exoplanet Survey Satellite (TESS) is about to provide full-frame images of almost the entire sky. The amount of stellar data to be analysed represents hundred…
The impact of a fossil magnetic field on dipolar mixed-mode frequencies in sub- and red-giant stars
L. Bugnet, V. Prat, S. Mathis +5
Stars more massive than M are known to develop a convective core during the main-sequence: the dynamo process triggered by this convection could be the origin of…
FliPer: A global measure of power density to estimate surface gravities of main-sequence Solar-like stars and red giants
L. Bugnet, R. A. GarcÃa, G. R. Davies +4
Asteroseismology provides global stellar parameters such as masses, radii or surface gravities using the mean global seismic parameters as well as the effective temperature for tho…