Journal Article

First <i>Kepler</i> results on compact pulsators – V. Slowly pulsating subdwarf B stars in short-period binaries

S. D. Kawaler, M. D. Reed, R. H. Østensen, S. Bloemen, D. W. Kurtz, A. C. Quint, R. Silvotti, A. S. Baran, E. M. Green, S. Charpinet, J. Telting, C. Aerts, G. Handler, H. Kjeldsen, J. Christensen-Dalsgaard, W. J. Borucki and D. G. Koch

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 409, issue 4, pages 1509-1517
Published in print December 2010 | ISSN: 0035-8711
Published online December 2010 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2010.17475.x
First Kepler results on compact pulsators – V. Slowly pulsating subdwarf B stars in short-period binaries

Show Summary Details

Preview

The survey phase of the Kepler Mission includes a number of hot subdwarf B (sdB) stars to search for non-radial pulsations. We present our analysis of two sdB stars that are found to be g-mode pulsators of the V1093 Her class. These two stars also display the distinct irradiation effect typical of sdB stars with a close M-dwarf companion with orbital periods of less than half a day. Because the orbital period is so short, the stars should be in synchronous rotation, and if so, the rotation period should imprint itself on the multiplet structure of the pulsations. However, we do not find clear evidence for such rotational splitting. Though the stars do show some frequency spacings that are consistent with synchronous rotation, they also display multiplets with splittings that are much smaller. Longer-duration time series photometry will be needed to determine if those small splittings are in fact rotational splitting, or caused by slow amplitude or phase modulation. Further data should also improve the signal-to-noise ratio, perhaps revealing lower-amplitude periodicities that could confirm the expectation of synchronous rotation. The pulsation periods seen in these stars show period spacings that are suggestive of high-overtone g-mode pulsations.

Keywords: stars: binaries: close; stars: oscillations; subdwarfs; stars: variables: general

Journal Article.  6168 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.