PAUNZEN, Ernst, Stefan HUEMMERICH, Klaus BERNHARD and Przemek WALCZAK. K2 observations of 95 Vir: delta Scuti pulsations in a chromospherically active star. Monthly Notices of the Royal Astronomical Society. Oxford: OXFORD UNIV PRESS, vol. 468, No 2, p. 2017-2023. ISSN 0035-8711. doi:10.1093/mnras/stx591. 2017.
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Basic information
Original name K2 observations of 95 Vir: delta Scuti pulsations in a chromospherically active star
Authors PAUNZEN, Ernst (40 Austria, guarantor, belonging to the institution), Stefan HUEMMERICH (276 Germany), Klaus BERNHARD (40 Austria) and Przemek WALCZAK (616 Poland).
Edition Monthly Notices of the Royal Astronomical Society, Oxford, OXFORD UNIV PRESS, 2017, 0035-8711.
Other information
Original language English
Type of outcome Article in a journal
Field of Study 10308 Astronomy
Country of publisher United Kingdom of Great Britain and Northern Ireland
Confidentiality degree is not subject to a state or trade secret
Impact factor Impact factor: 5.194
RIV identification code RIV/00216224:14310/17:00099898
Organization unit Faculty of Science
Doi http://dx.doi.org/10.1093/mnras/stx591
UT WoS 000399429600059
Keywords in English stars:activity; stars:individual: HD 123255; stars:variables:delta Scuti
Tags NZ, rivok
Tags International impact, Reviewed
Changed by Changed by: Ing. Nicole Zrilić, učo 240776. Changed: 6/4/2018 10:50.
Abstract
We have searched for photometric variability in 95 Vir, a fast rotating, chromospherically active early F-type star, which was observed in the framework of Campaign 6 of the Kepler K2 mission. Available literature information on 95 Vir was procured, and well-established calibrations were employed to verify the derived astrophysical parameters. We have investigated the location of our target star in the M-Bol versus log T-eff diagram, which provides information on the evolutionary status. We have discussed our results in detail, drawing on literature information and the theoretical predictions of state-of-the-art pulsation models, with the aim of unravelling the underlying variability mechanisms. From an analysis of 3400 long-cadence measurements, we have identified two main frequencies and several harmonics in our target star. We attribute the main frequency, f1 = 9.537 28 d(-1), to delta Scuti pulsations. The origin of the secondary signal, f2 = 1.071 29 d(-1), is less clear. We have investigated three possible interpretations of the low-frequency variation: binarity, pulsation and rotational modulation. Current evidence favours an interpretation of f 2 as a signature of the rotational period caused by the presence of cool star-spots, which goes along well with the observed chromospheric activity. However, phase-resolved spectroscopy is needed to verify this assumption. We briefly consider other chromospherically active delta Scuti stars that have been presented in the literature. A search for star-spot-induced photometric variability in these objects might be of great interest, as well as an investigation of the interplay between chromospheric and pulsational activity.
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