EPJ Web Conf.
Volume 160, 2017Seismology of the Sun and the Distant Stars 2016 – Using Today’s Successes to Prepare the Future – TASC2 & KASC9 Workshop – SPACEINN & HELAS8 Conference
|Number of page(s)||8|
|Section||Seismology: Stars Near and in The Main Sequence|
|Published online||27 October 2017|
The first K2 roAp star: HD 24355 pulsating in a distorted quadruploe mode
Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE, UK
2 Astrophysics Department, Keele University, Staffordshire, ST5 5BG UK
3 Astronomical Institute, School of Science, Tohoku University, Sendai, 980-8578, Japan
4 Copernicus Astronomical Center, Bartycka 18, Warsaw, PL-00-716, Poland
5 Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW, 2006, Australia
6 Thüringer Landessternwarte Tautenburg (TLS), Sternwarte 5, Tautenburg, D-07778, Germany
⋆ e-mail: firstname.lastname@example.org
Published online: 27 October 2017
We present an analysis of the first K2 observations of a rapidly oscillating Ap (roAp) star, HD 24355. The star was discovered to be a roAp star by , with a frequency of 224.31 d-1 (2596.18 μHz; P = 6.4 min) and an amplitude of 1.51 mmag in SuperWASP broadband photometry. Spectroscopic analysis of low-resolution spectra show the star to be an A5 Vp SrEu star. The high precision K2 data allow us to identify 13 rotationally split sidelobes to the main pulsation frequency. This is the largest number of sidelobes seen in a roAp star to date. We also see an unusual pulsational phase variation as the star rotates, showing this star to be the most distorted quadrupole roAp pulsator yet observed. Modelling of this star confirms its quadrupole nature, and allows us to constrain the magnetic field strength, angle of inclination and the angle of obliquity.
© Owned by the authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (http://creativecommons.org/licenses/by/4.0/).
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