Extends magnetogravity polarization formalism to arbitrary magnetic field geometries, revealing avoided crossings and mode conversion below a local field threshold.
A prevalence of dynamo-generated magnetic fields in the cores of intermediate-mass stars
2 Pith papers cite this work. Polarity classification is still indexing.
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Pith papers citing it
abstract
Magnetic fields play a role in almost all stages of stellar evolution. Most low-mass stars, including the Sun, show surface fields that are generated by dynamo processes in their convective envelopes. Intermediate-mass stars do not have deep convective envelopes, although 10% exhibit strong surface fields that are presumed to be residuals from the stellar formation process. These stars do have convective cores that might produce internal magnetic fields, and these might even survive into later stages of stellar evolution, but information has been limited by our inability to measure the fields below the stellar surface. Here we use asteroseismology to study the occurrence of strong magnetic fields in the cores of low- and intermediate-mass stars. We have measured the strength of dipolar oscillation modes, which can be suppressed by a strong magnetic field in the core, in over 3600 red giant stars observed by Kepler. About 20% of our sample show mode suppression but this fraction is a strong function of mass. Strong core fields only occur in red giants above 1.1 solar masses (1.1Msun), and the occurrence rate is at least 60% for intermediate-mass stars (1.6--2.0Msun), indicating that powerful dynamos were very common in the convective cores of these stars.
fields
astro-ph.SR 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
Synthetic spectra show that observational biases cause dipole mode visibilities to be overestimated by up to 20 percent on the red-giant branch, while partial energy preservation under magnetic damping can produce both present and absent mixed-mode signatures.
citing papers explorer
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Extending asteroseismic magnetometry across the diverse landscape of magnetic structures
Extends magnetogravity polarization formalism to arbitrary magnetic field geometries, revealing avoided crossings and mode conversion below a local field threshold.
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Oscillations of red giant stars with magnetic damping in the core. II. Mixed mode visibilities on the red-giant branch
Synthetic spectra show that observational biases cause dipole mode visibilities to be overestimated by up to 20 percent on the red-giant branch, while partial energy preservation under magnetic damping can produce both present and absent mixed-mode signatures.