Recently, the study of the CoRoT target HD 49933 showed evidence of variability of its magnetic activity. This was the first time that a stellar activity was detected using asteroseismic data. For the Sun and HD 49933, we observe an increase of the p-mode frequencies and a decrease of the maximum amplitude per radial mode when the activity level is higher. Moreover a similar behavior of the frequency shifts with frequency has been found between the Sun and HD 49933. We study 3 other targets of CoRoT as well, for which modes have been detected and well identified: HD 181420, HD 49385, and HD 52265 (which is hosting a planet). We show how the seismic parameters (frequency shifts and amplitude) vary during the observation of these stars.
@article{arxiv.1110.0875,
title = {Investigating stellar activity with CoRoT observations},
author = {S. Mathur and D. Salabert and R. A. Garcia and C. Regulo and J. Ballot and T. S. Metcalfe},
journal= {arXiv preprint arXiv:1110.0875},
year = {2011}
}
Comments
4 pages. To appear in the ASP proceedings of "The 61st Fujihara seminar: Progress in solar/stellar physics with helio- and asteroseismology", 13th-17th March 2011, Hakone, Japan