Does the Babcock-Leighton dynamo operate in rapidly rotating solar-type stars? Exploration using a 3D dynamo model at different rotation rates

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Vashishth, Vindya, Karak, Bidya Binay
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866912757920563200
author Vashishth, Vindya
Karak, Bidya Binay
author_facet Vashishth, Vindya
Karak, Bidya Binay
contents The Babcock-Leighton dynamo, which relies on the generation of a poloidal field through the decay and dispersal of tilted bipolar magnetic regions (BMRs), is a promising paradigm for explaining the features of the solar magnetic cycle. In rapidly rotating stars, BMRs are expected to emerge at high latitudes, which are less efficient in generating the poloidal field due to poor cross-equatorial cancellation. The operation of the Babcock-Leighton dynamo in rapidly rotating stars is therefore questionable. We, for the first time, using a 3D kinematic dynamo model, STABLE, explore this question. By taking large-scale flows from mean-field hydrodynamics models for stars rotating at different speeds, We conduct a series of dynamo simulations in rapidly rotating stars, exploring the following four cases of spot deposition, each based on a different assumption about toroidal flux tube rise: (i) radial rise, (ii) parallel rise to the rotation axis, (iii) parallel rise combined with an increase in Joy's law slope with the stellar rotation rate, and (iv) increasing time delay and spot size. We find cyclic magnetic fields in all cases except case IV of the 1-day rotating star, for which the magnetic field is irregular. For the parallel-rise cases, the magnetic field becomes quadrupolar, and for all other cases, it is dipolar. Our work demonstrates that the Babcock-Leighton dynamo may operate even in rapidly rotating stars with starspots appearing at higher latitudes.
format Preprint
id arxiv_https___arxiv_org_abs_2512_10508
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Does the Babcock-Leighton dynamo operate in rapidly rotating solar-type stars? Exploration using a 3D dynamo model at different rotation rates
Vashishth, Vindya
Karak, Bidya Binay
Solar and Stellar Astrophysics
Instrumentation and Methods for Astrophysics
The Babcock-Leighton dynamo, which relies on the generation of a poloidal field through the decay and dispersal of tilted bipolar magnetic regions (BMRs), is a promising paradigm for explaining the features of the solar magnetic cycle. In rapidly rotating stars, BMRs are expected to emerge at high latitudes, which are less efficient in generating the poloidal field due to poor cross-equatorial cancellation. The operation of the Babcock-Leighton dynamo in rapidly rotating stars is therefore questionable. We, for the first time, using a 3D kinematic dynamo model, STABLE, explore this question. By taking large-scale flows from mean-field hydrodynamics models for stars rotating at different speeds, We conduct a series of dynamo simulations in rapidly rotating stars, exploring the following four cases of spot deposition, each based on a different assumption about toroidal flux tube rise: (i) radial rise, (ii) parallel rise to the rotation axis, (iii) parallel rise combined with an increase in Joy's law slope with the stellar rotation rate, and (iv) increasing time delay and spot size. We find cyclic magnetic fields in all cases except case IV of the 1-day rotating star, for which the magnetic field is irregular. For the parallel-rise cases, the magnetic field becomes quadrupolar, and for all other cases, it is dipolar. Our work demonstrates that the Babcock-Leighton dynamo may operate even in rapidly rotating stars with starspots appearing at higher latitudes.
title Does the Babcock-Leighton dynamo operate in rapidly rotating solar-type stars? Exploration using a 3D dynamo model at different rotation rates
topic Solar and Stellar Astrophysics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2512.10508