English

Evolution of cataclysmic variables under different magnetic braking prescriptions

Solar and Stellar Astrophysics 2026-02-06 v1

Abstract

Context. The evolution of cataclysmic variables (CVs) - interacting binaries where a low-mass donor transfers matter to a white dwarf via an accretion disk - is critically controlled by magnetic braking (MB). Significant uncertainties persist regarding how distinct MB formalisms influence CV evolutionary pathways. Aims. We performed systematic simulations of CV evolution under five MB prescriptions using the MESA code: the classical Skumanich law and the Matt, Reiners & Mohanty (RM12), intermediate, and convection-boosted formalisms. Primary objectives included investigating their impact on orbital period distributions, mass-transfer rates, donor star evolution, and period gap characteristics. Methods. Evolutionary sequences were computed across all MB frameworks. We analyzed their effects on key observables: orbital period evolution, accretion rates, and period gap morphology. Results. Magnetic braking prescription selection fundamentally determines whether CV systems develop the characteristic period gap. The intermediate prescription provides optimal consistency with observations of nonmagnetic CVs, simultaneously reproducing the gap location and donor properties. Strong braking models (e.g., Skumanich) produce clear detachment phases, while self-consistent regulation models (Matt12 and RM12) maintain weak angular momentum loss and fail to form a gap, making them more prone to magnetic CVs. Conclusions. The presence or absence of the period gap is primarily governed by the strength and behavior of MB before the donor becomes fully convective. Future studies must further incorporate the regulatory effects of magnetic fields on donor structure to accurately predict the period distribution characteristics of magnetic CVs.

Keywords

Cite

@article{arxiv.2602.05260,
  title  = {Evolution of cataclysmic variables under different magnetic braking prescriptions},
  author = {Bingyao Zhou and Chunhua Zhu and Guoliang Lü and Sufen Guo and Helei Liu and Farkhodjon Khamrakulov},
  journal= {arXiv preprint arXiv:2602.05260},
  year   = {2026}
}

Comments

14 pages, 13 figures, 1 table

R2 v1 2026-07-01T09:37:09.868Z