The cradle of nonlinear asteroseismology: observations of oscillation mode variability in compact pulsating stars
Weikai Zong,
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing 102206, China and Department of Astronomy, Beijing Normal University, Beijing 100875, China. Corresponding author:
weikai.zong@bnu.edu.cn
Gérard Vauclair,
IRAP, CNRS, Université de Toulouse, CNES, 14 Avenue Edouard Belin, 31400 Toulouse, France
Jian-Ning Fu,
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing 102206, China and Department of Astronomy, Beijing Normal University, Beijing 100875, China
Xiao-Yu Ma,
Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University, Beijing 102206, China and Department of Astronomy, Beijing Normal University, Beijing 100875, China
Abstract
We briefly review progress in developing a pathway to nonlinear astereoseismology, both from theoretical and observational aspects. As predicted by the theory of weak nonlinear interactions between resonant modes, their amplitude and frequency can be modulated according to various kinds of patterns. However, those subtle modulations could hardly be well characterized from ground-based photometric monitoring. The Kepler spacecraft offered a new window to find clear-cut evidence of well-determined amplitude and frequency modulations, leading to the first discoveries of such variations in pulsating white dwarf and hot B subdwarf stars. Fol-lowing that direction, a systematic survey of oscillation mode properties in compact pulsators monitored by Kepler suggests that mode variability is likely a common phenomenon, which remain unaccounted for by standard linear non-radial pulsation theory. To reach this conclusion firmly, the survey has now been extended to a larger context including compact stars observed by K2 and TESS. We expect that this extended survey will help to constrain key parameters governing weak nonlinear effects in stellar oscillations.
Keywords : nonlinear theory, amplitude modulation, frequency modulation, hot B subdwarfs, white dwarfs
Pour citer cet article
Weikai Zong, Stéphane Charpinet, Gérard Vauclair, Jian-Ning Fu & Xiao-Yu Ma, «The cradle of nonlinear asteroseismology: observations of oscillation mode variability in compact pulsating stars», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 92 - Année 2023, Numéro 2 - Proceedings of the 10th Meeting on Hot Subdwarfs and Related Objects, 126-133 URL : http://popups.ulg.be/0037-9565/index.php?id=11305.
