L. A. Balona, M. Breger, G. Catanzaro, M. S. Cunha, G. Handler, Z. Kołaczkowski, D. W. Kurtz, S. J. Murphy, E. Niemczura, M. Paparó, B. Smalley, R. Szabó, K. Uytterhoeven, J. L. Christiansen, K. Uddin, M. C. Stumpe
Abstract
We show that the star KIC 4840675 observed by Kepler is composed of three stars with a rapidly rotating A-type star and two solar-type fainter companions. The A-type star is a δ Scuti variable with a dominant mode and many other modes of lower amplitude, including several low-frequency variations. The low-frequency variation with highest amplitude can be interpreted as rotational modulation with the light curve changing with time. However, the most interesting aspect of this star is a triplet of independent modes in the range 118–129 d-1 (1.4–1.5 mHz), which is far outside the range of typical δ Scuti frequencies. We discuss the possibility that these modes could be solar-like oscillations, oscillations of the roAp type or due to an unseen pulsating compact companion.
Keywords
asteroseismology – binaries: spectroscopic – stars: individual: KIC 4840675 – stars: oscillations – stars: variables: δ Scuti
Monthly Notices of the Royal Astronomical Society
Volume 424, Issue 2, Page 1187
2012 August
