M. Breger, M. Hareter, Markus Endl, R. Kuschnig, W. W. Weiss, J. M. Matthews, D. B. Guenther, A. F. J. Moffat, J. F. Rowe, S. M. Rucinski, D. Sasselov
The Praesepe cluster contains a number of Delta Sct and Gamma Dor pulsators.
Asteroseismology of cluster stars is simplified by the common distance, age and
stellar abundances. Since asteroseismology requires a large number of known
frequencies, the small pulsation amplitudes of these stars require space
satellite campaigns. The present study utilizes photometric MOST satellite
measurements in order to determine the pulsation frequencies of two evolved (EP
Cnc, BT Cnc) and two main-sequence (BS Cnc, HD 73872) Delta Sct stars in the
Praesepe cluster. The frequency analysis of the 2008 and 2009 data detected up
to 34 frequencies per star with most amplitudes in the submillimag range. In BS
Cnc, two modes showed strong amplitude variability between 2008 and 2009. The
frequencies ranged from 0.76 to 41.7 c/d. After considering the different
evolutionary states and mean stellar densities of these four stars, the
differences and large ranges in frequency remain.
View original:
http://arxiv.org/abs/1201.0892
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