Work

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

Year: 2025

Type: article

Abstract: ABSTRACT 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 $\alpha$-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 $\alpha$ reflects transitions between distinct accretion states rather than differences in global disc properties.

Source: Monthly Notices of the Royal Astronomical Society

DOI: 10.1093/mnras/staf2220

Authors: Cristiano Longarini, Cathie J Clarke

Institution: University of Cambridge

Language: English

Topic: Astrophysics and Star Formation Studies

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,046

Funder: Science and Technology Facilities Council