Accretion bottleneck in protoplanetary discs: the role of the stellar spin

Fuente: arXiv
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Main Authors: Longarini, Cristiano, Clarke, Cathie
Format: Preprint
Published: 2025
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author Longarini, Cristiano
Clarke, Cathie
author_facet Longarini, Cristiano
Clarke, Cathie
contents We investigate angular momentum transport and accretion properties in a sample of protoplanetary discs with dynamical measurements of stellar masses, disc masses, and scale radii. From these data we infer effective $α$-viscosities, finding a remarkably broad range spanning over three orders of magnitude. This spread correlates with the stellar rotation period: systems with shorter periods exhibit significantly lower accretion rates, suggesting that they are undergoing at least temporary episodes of accretion bottleneck. We interpret this behaviour within the framework of magnetospheric accretion models, where the transition between steady accretion and the propeller regime is set by the relative locations of the co-rotation and magnetospheric radii. Our results indicate that stellar spin is a key parameter in regulating mass transfer from the disc to the star, and provide new evidence that the observed dispersion in $α$ reflects transitions between distinct accretion states rather than differences in global disc properties.
format Preprint
id arxiv_https___arxiv_org_abs_2512_09638
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Accretion bottleneck in protoplanetary discs: the role of the stellar spin
Longarini, Cristiano
Clarke, Cathie
Earth and Planetary Astrophysics
Solar and Stellar Astrophysics
We investigate angular momentum transport and accretion properties in a sample of protoplanetary discs with dynamical measurements of stellar masses, disc masses, and scale radii. From these data we infer effective $α$-viscosities, finding a remarkably broad range spanning over three orders of magnitude. This spread correlates with the stellar rotation period: systems with shorter periods exhibit significantly lower accretion rates, suggesting that they are undergoing at least temporary episodes of accretion bottleneck. We interpret this behaviour within the framework of magnetospheric accretion models, where the transition between steady accretion and the propeller regime is set by the relative locations of the co-rotation and magnetospheric radii. Our results indicate that stellar spin is a key parameter in regulating mass transfer from the disc to the star, and provide new evidence that the observed dispersion in $α$ reflects transitions between distinct accretion states rather than differences in global disc properties.
title Accretion bottleneck in protoplanetary discs: the role of the stellar spin
topic Earth and Planetary Astrophysics
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2512.09638