The influence of the environment on the spin evolution of low-mass stars - I. External photoevaporation of circumstellar discs
Abstract
Massive stars are strong sources of far-ultraviolet radiation that can be hostile to the evolution of protoplanetary discs, driving mass-loss by external photoevaporation and shortening disc-dissipation time-scales. Their effect may also reduce the time-scale of angular momentum exchanges between the disc and host star during the early pre-main-sequence phase. To improve our understanding of the environmental influence on the rotational history of stars, we developed a model that considers the influence of the local far-ultraviolet radiation on the spin evolution of low mass stars. Our model includes an assumption of disc locking, which fixes the rotation rate during the star-disc-interaction phase, with the duration of this phase parametrized as a function of the local far-ultraviolet radiation and stellar mass (in the range of 0.1-1.3 M⊙). In this way, we demonstrate how the feedback from massive stars can significantly influence the spin evolution of stars and explain the mass dependence observed in period-mass distributions of young regions like Upper Sco and NGC 2264. The high far-ultraviolet environments of high-mass stars can skew the period distribution of surrounding stars towards fast-rotation, explaining the excess of fast-rotating stars in the open cluster h Per. The proposed link between rotation and the pre-main-sequence environment opens new avenues for interpreting the rotational distributions of young stars. For example, we suggest that stellar rotation may be used as a tracer for the primordial ultraviolet irradiation for stars up to ~1 Gyr, which offers a potential method to connect mature planetary systems to their birth environment.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- December 2021
- DOI:
- 10.1093/mnras/stab2772
- arXiv:
- arXiv:2109.10296
- Bibcode:
- 2021MNRAS.508.3710R
- Keywords:
-
- stars: evolution;
- stars: low-mass;
- stars: pre-main-sequence;
- stars: rotation;
- stars: solar-type;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 20 pages, 7 figures. Submitted to MNRAS