A spectroscopic and photometric investigation of the mercury-manganese star KIC 6128830
Authors | |
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Year of publication | 2018 |
Type | Article in Periodical |
Magazine / Source | Monthly Notices of the Royal Astronomical Society |
MU Faculty or unit | |
Citation | |
Web | http://dx.doi.org/10.1093/mnras/stx2974 |
Doi | http://dx.doi.org/10.1093/mnras/stx2974 |
Keywords | stars: abundances; stars: atmospheres; stars: chemically peculiar; stars: individual: KIC 6128830; stars: variables: general |
Description | The advent of space-based photometry provides the opportunity for the first precise characterizations of variability in mercury-manganese (HgMn/CP3) stars, which might advance our understanding of their internal structure. We have carried out a spectroscopic and photometric investigation of the candidate CP3 star KIC 6128830. A detailed abundance analysis based on newly acquired high-resolution spectra was performed, which confirms that the star's abundance pattern is fully consistent with its proposed classification. Photometric variability was investigated using 4 yr of archival Kepler data. In agreement with results from the literature, we have identified a single significant and independent frequency f(1) = 0.2065424 d(-1) with a peak-to-peak amplitude of similar to 3.4 mmag and harmonic frequencies up to 5f(1). Drawing on the predictions of state-of-the-art pulsation models and information on evolutionary status, we discuss the origin of the observed light changes. Our calculations predict the occurrence of g-mode pulsations at the observed variability frequency. On the other hand, the strictly mono-periodic nature of the variability strongly suggests a rotational origin. While we prefer the rotational explanation, the present data leave some uncertainty. |
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