Using ZDI maps to determine magnetic forces and torques at the photospheres of early-type stars
Abstract
We use the magnetic field components measured by Zeeman Doppler imaging (ZDI) to calculate the stellar surface force and torque due to magnetic stresses for the fast rotators σ Ori E, 36 Lyn, and CU Vir, and the slow rotator τ Sco. If we assume the stars have spherical photospheres, the estimated torques give spin-down time-scales no larger than 7 × 105 yr. For σ Ori E, the predicted spin-down time-scale, ≃ 6000 yr, is much less than the observationally measured time-scale of ≃ 106 yr. However, for CU Vir, we find that the spin-down time-scale from its ZDI map is 7 × 105 yr in good agreement with its average rate of spin-down from 1960 to 2010.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- May 2024
- DOI:
- 10.1093/mnras/stae1030
- arXiv:
- arXiv:2404.10161
- Bibcode:
- 2024MNRAS.530.2840M
- Keywords:
-
- stars: early-type;
- stars: magnetic field;
- stars: rotation;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- To appear in MNRAS