KIC 4768731: a bright long-period roAp star in the Kepler field
Article
Article Title | KIC 4768731: a bright long-period roAp star in the Kepler field |
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ERA Journal ID | 1074 |
Article Category | Article |
Authors | Smalley, B. (Author), Niemczura, E. (Author), Murphy, S. J. (Author), Lehmann, H. (Author), Kurtz, D. W. (Author), Holdsworth, D. L. (Author), Cunha, M. S. (Author), Balona, L. A. (Author), Briquet, M. (Author), Bruntt, H. (Author), De Cat, P. (Author), Lampens, P. (Author), Thygesen, A. O. (Author) and Uytterhoeven, K. (Author) |
Journal Title | Monthly Notices of the Royal Astronomical Society |
Journal Citation | 452 (4), pp. 3334-3345 |
Number of Pages | 12 |
Year | 2015 |
Publisher | Oxford University Press |
Place of Publication | United Kingdom |
ISSN | 0035-8711 |
1365-2966 | |
Digital Object Identifier (DOI) | https://doi.org/10.1093/mnras/stv1515 |
Web Address (URL) | https://academic.oup.com/mnras/article/452/4/3334/1058584 |
Abstract | We report the identification of 61.45 d−1 (711.2 μHz) oscillations, with amplitudes of 62.6 μmag, in KIC 4768731 (HD 225914) using Kepler photometry. This relatively bright (V = 9.17) chemically peculiar star with spectral type A5 Vp SrCr(Eu) has previously been found to exhibit rotational modulation with a period of 5.21 d. Fourier analysis reveals a simple dipole pulsator with an amplitude that has remained stable over a 4-yr time span, but with a frequency that is variable. Analysis of high-resolution spectra yields stellar parameters of Teff = 8100 ± 200 K, log g = 4.0 ± 0.2, [Fe/H] = +0.31 ± 0.24 and v sin i = 14.8 ± 1.6 km s−1. Line profile variations caused by rotation are also evident. Lines of Sr, Cr, Eu, Mg and Si are strongest when the star is brightest, while Y and Ba vary in antiphase with the other elements. The abundances of rare earth elements are only modestly enhanced compared to other roAp stars of similar Teff and log g. Radial velocities in the literature suggest a significant change over the past 30 yr, but the radial velocities presented here show no significant change over a period of 4 yr. |
Keywords | Asteroseismology; Stars: abundances; Stars: chemically peculiar; Stars: individual: KIC 4768731; Stars: oscillations; Techniques: photometric; Astrophysics - Solar and Stellar Astrophysics |
ANZSRC Field of Research 2020 | 510109. Stellar astronomy and planetary systems |
Public Notes | This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved. |
Byline Affiliations | Keele University, United Kingdom |
University of Wroclaw, Poland | |
University of Sydney | |
Karl Schwarzschild Observatory, Germany | |
University of Central Lancashire, United Kingdom | |
University of Porto, Portugal | |
South African Astronomical Observatory, South Africa | |
University of Liege, Belgium | |
Aarhus University, Denmark | |
Royal Observatory of Belgium | |
Heidelberg University, Germany | |
Institute of Astrophysics of the Canary Islands, Spain | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q73w5/kic-4768731-a-bright-long-period-roap-star-in-the-kepler-field
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