Bibcode
Mathur, S.; García, R. A.; Régulo, C.; Creevey, O. L.; Ballot, J.; Salabert, D.; Arentoft, T.; Quirion, P.-O.; Chaplin, W. J.; Kjeldsen, H.
Bibliographical reference
Astronomy and Astrophysics, Volume 511, id.A46
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2
2010
Journal
Citations
221
Refereed citations
176
Description
Context. Helioseismology has enabled us to better understand the solar
interior, while also allowing us to better constrain solar models. But
now is a tremendous epoch for asteroseismology as space missions
dedicated to studying stellar oscillations have been launched within the
last years (MOST and CoRoT). CoRoT has already proved valuable results
for many types of stars, while Kepler, which was launched in March 2009,
will provide us with a huge number of seismic data very soon. This is an
opportunity to better constrain stellar models and to finally understand
stellar structure and evolution. Aims: The goal of this research
work is to estimate the global parameters of any solar-like oscillating
target in an automatic manner. We want to determine the global
parameters of the acoustic modes (large separation, range of excited
pressure modes, maximum amplitude, and its corresponding frequency),
retrieve the surface rotation period of the star and use these results
to estimate the global parameters of the star (radius and mass).
Methods: To prepare for the arrival and the analysis of hundreds of
solar-like oscillating stars, we have developed a robust and automatic
pipeline, which was partially adapted from helioseismic methods. The
pipeline consists of data analysis techniques, such as Fast Fourier
Transform, wavelets, autocorrelation, as well as the application of
minimisation algorithms for stellar-modelling. Results: We apply
our pipeline to some simulated lightcurves from the asteroFLAG team and
the Aarhus-asteroFLAG simulator, and obtain results that are consistent
with the input data to the simulations. Our strategy gives correct
results for stars with magnitudes below 11 with only a few 10% of bad
determinations among the reliable results. We then apply the pipeline to
the Sun and three CoRoT targets. In particular we determine the large
separation and radius of the Sun, HD49933, HD181906, and HD181420.
Related projects
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur