International audience
Multiple theories predict the existence of prograde fluid jets in the solar tachocline. We find helioseismic evidence of a prograde jet near 60° latitude in N and S hemispheres that persists through almost all of the current solar cycle. This evidence favors a hydrodynamic origin for the jet, from global instability of the differential rotation...
Stellar magnetic fields are poorly understood, but are known to be important for stellar evolution and exoplanet habitability. They drive stellar activity, which is the main observational constraint on theoretical models for magnetic field generation and evolution. Starspots are the main manifestation of the magnetic fields at the stellar...
Astrophysics and Space Science, 316, pp. 1-4, http://dx.doi.org./10.1007/s10509-008-9771-1
In order to make asteroseismology a powerful tool to explore stellar interiors, different numerical codes should give the same oscillation frequencies for the same input physics. Any differences found when comparing the numerical values of the eigenfrequencies will be an important piece of information regarding the numerical structure of the...
We present recent work undertaken by the Evolution and Seismic Tools Activity (ESTA) team of the CoRoT Seismology Working Group. The new ESTA-Task 3 aims at testing, comparing and optimising stellar evolution codes which include microscopic diffusion of the chemical elements resulting from pressure, temperature and concentration gradients. The...
International audience
International audience
International audience
Nineteen of the ∼40 RR Lyr stars in the Kepler field have been identified as candidate non-Blazhko (or unmodulated) stars. In this paper we present the results of Fourier decomposition of the time-series photometry of these stars acquired during the first 417 d of operation (Q0–Q5) of the Kepler telescope. Fourier parameters based on ∼18 400...
Splitting of the Sun's global oscillation frequencies by large-scale ows can be used to investigate how rotation varies with radius and latitude within the solar interior. The nearly uninterrupted observations by GONG yield oscillation power spectra with high duty cycle and signal-to-noise ratio. Frequency split-tings derived from GONG...
Astronomy and Astrophysics Review, 14, pp. 217-360, http://dx.doi.org./10.1007/s00159-007-0007-0
Astronomy and Astrophysics Review, 14, pp. 217-360, http://dx.doi.org./10.1007/s00159-007-0007-0
International audience
Aims. In this work, we determine the expected yield of detections of solar-like oscillations for the targets of the foreseen PLATO ESA mission. Our estimates are based on a study of the detection probability, which takes into account the properties of the target stars, using the information available in the PIC 1.1.0, including the current best...
We present the work undertaken by the Evolution and Seismic Tools Activity (ESTA) team of the CoRoT Seismology Working Group. We have focused on two main tasks: Task 1 - now finished - has aimed at testing, comparing and optimising seven stellar evolution codes which will be used to model the internal structure and evolution of the CoRoT target...