J 2017

K2 observations of 95 Vir: delta Scuti pulsations in a chromospherically active star

PAUNZEN, Ernst, Stefan HUEMMERICH, Klaus BERNHARD and Przemek WALCZAK

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

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

United Kingdom of Great Britain and Northern Ireland

Confidentiality degree

není předmětem státního či obchodního tajemství

Impact factor

Impact factor: 5.194

RIV identification code

RIV/00216224:14310/17:00099898

Organization unit

Faculty of Science

DOI

UT WoS

000399429600059

Keywords in English

stars:activity; stars:individual: HD 123255; stars:variables:delta Scuti

Tags

Tags

International impact, Reviewed
Změněno: 6/4/2018 10:50, Ing. Nicole Zrilić

Abstract

V originále

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.