---
_id: '13445'
abstract:
- lang: eng
  text: Rotation is typically assumed to induce strictly symmetric rotational splitting
    into the rotational multiplets of pure p- and g-modes. However, for evolved stars
    exhibiting mixed modes, avoided crossings between different multiplet components
    are known to yield asymmetric rotational splitting, in particular for near-degenerate
    mixed-mode pairs, where notional pure p-modes are fortuitously in resonance with
    pure g-modes. These near-degeneracy effects have been described in subgiants,
    but their consequences for the characterization of internal rotation in red giants
    have not previously been investigated in detail, in part owing to theoretical
    intractability. We employ new developments in the analytic theory of mixed-mode
    coupling to study these near-resonance phenomena. In the vicinity of the most
    p-dominated mixed modes, the near-degenerate intrinsic asymmetry from pure rotational
    splitting increases dramatically over the course of stellar evolution, and it
    depends strongly on the mode-mixing fraction ζ. We also find that a linear treatment
    of rotation remains viable for describing the underlying p- and g-modes, even
    when it does not for the resulting mixed modes undergoing these avoided crossings.
    We explore observational consequences for potential measurements of asymmetric
    mixed-mode splitting, which has been proposed as a magnetic-field diagnostic.
    Finally, we propose improved measurement techniques for rotational characterization,
    exploiting the linearity of rotational effects on the underlying p/g-modes, while
    still accounting for these mixed-mode coupling effects.
article_number: '18'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: J. M. Joel
  full_name: Ong, J. M. Joel
  last_name: Ong
- first_name: Lisa Annabelle
  full_name: Bugnet, Lisa Annabelle
  id: d9edb345-f866-11ec-9b37-d119b5234501
  last_name: Bugnet
  orcid: 0000-0003-0142-4000
- first_name: Sarbani
  full_name: Basu, Sarbani
  last_name: Basu
citation:
  ama: Ong JMJ, Bugnet LA, Basu S. Mode mixing and rotational splittings. I. Near-degeneracy
    effects revisited. <i>The Astrophysical Journal</i>. 2022;940(1). doi:<a href="https://doi.org/10.3847/1538-4357/ac97e7">10.3847/1538-4357/ac97e7</a>
  apa: Ong, J. M. J., Bugnet, L. A., &#38; Basu, S. (2022). Mode mixing and rotational
    splittings. I. Near-degeneracy effects revisited. <i>The Astrophysical Journal</i>.
    American Astronomical Society. <a href="https://doi.org/10.3847/1538-4357/ac97e7">https://doi.org/10.3847/1538-4357/ac97e7</a>
  chicago: Ong, J. M. Joel, Lisa Annabelle Bugnet, and Sarbani Basu. “Mode Mixing
    and Rotational Splittings. I. Near-Degeneracy Effects Revisited.” <i>The Astrophysical
    Journal</i>. American Astronomical Society, 2022. <a href="https://doi.org/10.3847/1538-4357/ac97e7">https://doi.org/10.3847/1538-4357/ac97e7</a>.
  ieee: J. M. J. Ong, L. A. Bugnet, and S. Basu, “Mode mixing and rotational splittings.
    I. Near-degeneracy effects revisited,” <i>The Astrophysical Journal</i>, vol.
    940, no. 1. American Astronomical Society, 2022.
  ista: Ong JMJ, Bugnet LA, Basu S. 2022. Mode mixing and rotational splittings. I.
    Near-degeneracy effects revisited. The Astrophysical Journal. 940(1), 18.
  mla: Ong, J. M. Joel, et al. “Mode Mixing and Rotational Splittings. I. Near-Degeneracy
    Effects Revisited.” <i>The Astrophysical Journal</i>, vol. 940, no. 1, 18, American
    Astronomical Society, 2022, doi:<a href="https://doi.org/10.3847/1538-4357/ac97e7">10.3847/1538-4357/ac97e7</a>.
  short: J.M.J. Ong, L.A. Bugnet, S. Basu, The Astrophysical Journal 940 (2022).
date_created: 2023-08-01T14:20:41Z
date_published: 2022-11-16T00:00:00Z
date_updated: 2023-09-06T07:27:45Z
day: '16'
doi: 10.3847/1538-4357/ac97e7
extern: '1'
external_id:
  arxiv:
  - '2210.01928'
intvolume: '       940'
issue: '1'
keyword:
- Space and Planetary Science
- Astronomy and Astrophysics
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://arxiv.org/abs/2210.01928
month: '11'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
  eissn:
  - 1538-4357
  issn:
  - 0004-637X
publication_status: published
publisher: American Astronomical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: Mode mixing and rotational splittings. I. Near-degeneracy effects revisited
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 940
year: '2022'
...