Bibcode
García, R. A.; Régulo, C.; Samadi, R.; Ballot, J.; Barban, C.; Benomar, O.; Chaplin, W. J.; Gaulme, P.; Appourchaux, T.; Mathur, S.; Mosser, B.; Toutain, T.; Verner, G. A.; Auvergne, M.; Baglin, A.; Baudin, F.; Boumier, P.; Bruntt, H.; Catala, C.; Deheuvels, S.; Elsworth, Y.; Jiménez-Reyes, S. J.; Michel, E.; Pérez Hernández, F.; Roxburgh, I. W.; Salabert, D.
Bibliographical reference
Astronomy and Astrophysics, Volume 506, Issue 1, 2009, pp.41-50
Advertised on:
10
2009
Journal
Citations
102
Refereed citations
81
Description
Context: The F8 star HD 181906 (effective temperature ˜6300 K) was
observed for 156 days by the CoRoT satellite during the first long run
in the direction of the galactic centre. Analysis of the data reveals a
spectrum of solar-like acoustic oscillations. However, the faintness of
the target (mv = 7.65) means the signal-to-noise (S/N) in the
acoustic modes is quite low, and this low S/N leads to complications in
the analysis. Aims: We extract global variables of the star, as
well as key parameters of the p modes observed in the power spectrum of
the lightcurve. Methods: The power spectrum of the lightcurve, a
wavelet transform and spot fitting were used to obtain the average
rotation rate of the star and its inclination angle. Then, the
autocorrelation of the power spectrum and the power spectrum of the
power spectrum were used to properly determine the large separation.
Finally, estimations of the mode parameters were done by maximizing the
likelihood of a global fit, where several modes were fit simultaneously.
Results: We have been able to infer the mean surface rotation rate
of the star (~4 μHz) with indications of the presence of surface
differential rotation, the large separation of the p modes (~87 μHz),
hence also the “ridges” corresponding to overtones of the
acoustic modes.
CoRoT (Convection, Rotation and planetary Transits) is a minisatellite
developed by the French Space agency CNES in collaboration with the
Science Programmes of ESA, Austria, Belgium, Brazil, Germany and Spain.
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