Recent work suggests that inwardly propagating internal gravity waves (IGWs) within a star can be fully converted to outward magnetic waves if they encounter a sufficiently strong magnetic field. The resulting magnetic waves dissipate as they propagate outward to regions with lower Alfvén velocity. While tidal forcing is known to excite IGWs, this conversion and subsequent damping of magnetic waves have not been explored as a tidal dissipation mechanism. In particular, stars with sufficiently strong magnetic fields could fully dissipate tidally excited waves, yielding the same tidal evolution as the previously studied “traveling wave regime.” Here, we evaluate the viability of this mechanism using stellar models of stars with convective cores (F-type stars in the mass range of 1.2–1.6 M _⊙), which were previously thought to be weakly tidally dissipative (due to the absence of nonlinear gravity-wave breaking). The criterion for wave conversion to operate is evaluated for each stellar mass using the properties of each star’s interior along with estimates of the magnetic field produced by a convective core dynamo under the assumption of equipartition between kinetic (convective) and magnetic energies. Our main result is that this previously unexplored source of efficient tidal dissipation can operate in stars within this mass range for significant fractions of their lifetimes. This tidal dissipation mechanism appears to be consistent with the observed inspiral of WASP-12b and more generally could play an important role in the orbital evolution of hot Jupiters—and to lower-mass ultra-short-period planets—orbiting F-type stars.

中文翻译：

---

通过恒星磁场的有效潮汐耗散机制

最近的研究表明，如果恒星内向内传播的内部重力波（IGW）遇到足够强的磁场，它们可以完全转换为向外的磁波。由此产生的磁波在向外传播到阿尔文速度较低的区域时消散。虽然已知潮汐力会激发 IGW，但这种转换和随后的磁波阻尼尚未作为潮汐耗散机制进行探索。特别是，具有足够强磁场的恒星可以完全消散潮汐激发波，产生与先前研究的“行波状态”相同的潮汐演化。在这里，我们使用具有对流核心的恒星（质量范围为 1.2-1.6 的 F 型恒星）的恒星模型来评估该机制的可行性中号 _⊙），以前被认为是弱潮汐耗散的（由于不存在非线性重力波破碎）。使用每颗恒星内部的特性以及在动能（对流）和磁能之间均分的假设下对对流核心发电机产生的磁场的估计，对每个恒星质量进行波转换操作的标准进行评估。我们的主要结果是，这种以前未经探索的有效潮汐耗散源可以在这个质量范围内的恒星中运行，并持续其寿命的很大一部分。这种潮汐耗散机制似乎与观测到的 WASP-12b 的螺旋运动一致，更广泛地说，可能在热木星以及绕 F 型恒星运行的低质量超短周期行星的轨道演化中发挥重要作用。