Pulsational frequency and amplitude modulation in the δ Sct star KIC 7106205

Bowman, Dominic and Kurtz, Donald Wayne orcid iconORCID: 0000-0002-1015-3268 (2014) Pulsational frequency and amplitude modulation in the δ Sct star KIC 7106205. Monthly Notices of the Royal Astronomical Society, 444 (2). pp. 1909-1918.

[thumbnail of publishers version]
PDF (publishers version) - Published Version

Official URL: http://adsabs.harvard.edu/abs/2014MNRAS.444.1909B


Analysis of the Kepler δ Sct star KIC 7106205 showed amplitude modulation in a single pressure mode, whilst all other pressure and gravity modes remained stable in amplitude and phase over the 1470 d length of the data set. The Kepler data set was divided into a series with time bins of equal length for which consecutive Fourier transforms were calculated. An optimum fixed frequency, calculated from a least-squares fit of all data, allowed amplitude and phase of each pulsation mode for each time bin to be tracked. The single pressure mode at ν = 13.3942 d-1 changed significantly in amplitude, from 5.16 ± 0.03 to 0.53 ± 0.06 mmag, but also varied quasi-sinusoidally in phase, with a characteristic period similar to the length of the data set. All other p and g modes were stable in both amplitude and phase, which is clear evidence that the visible pulsation mode energy is not conserved within this star. Possible causes of the observed amplitude and phase modulation and the missing mode energy are discussed.

Repository Staff Only: item control page