Bibcode
Salabert, D.; Régulo, C.; Ballot, J.; García, R. A.; Mathur, S.
Bibliographical reference
Astronomy and Astrophysics, Volume 530, id.A127
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6
2011
Journal
Citations
47
Refereed citations
29
Description
We study the frequency dependence of the frequency shifts of the
low-degree p modes measured in the F5V star HD 49933, by analyzing the
second run of observations collected by the CoRoT satellite. The 137-day
light curve is divided into two subseries corresponding to periods of
low and high stellar activity. The activity-frequency relationship is
obtained independently from the analysis of the mode frequencies
extracted by both a local and a global peak-fitting analyses, and from a
cross-correlation technique in the frequency range between 1450 μHz
and 2500 μHz. The three methods return consistent results. We show
that the frequency shifts measured in HD 49933 present a frequency
dependence with a clear increase with frequency, reaching a maximal
shift of about 2 μHz around 2100 μHz. Similar variations are
obtained between the l = 0 and l = 1 modes. At higher frequencies, the
frequency shifts show indications of a downturn followed by an upturn,
consistent between the l = 0 and 1 modes. We show that the frequency
variation of the p-mode frequency shifts of the solar-like oscillating
star HD 49933 has a comparable shape to the one observed in the Sun,
which is understood to arise from changes in the outer layers due to its
magnetic activity.
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