Aims. We investigate possible driving mechanisms of volcanic activity on rocky super-Earths with masses exceeding 3-4 Mearth. Due to high gravity and pressures in the mantles of these planets, melting in deep mantle layers can be suppressed, even if the energy releae due to tidal heating and radioactive decay is substantial. Here we investigate whether a newly identified heating mechanism, namely induction heating by the star's magnetic field, can drive volcanic activity on these planets due to its unique heating pattern in the very upper part of the mantle. In this region the pressure is not yet high enough to preclude the melt formation. Methods. Using the super-Earth HD 3167b as an example, we calculate induction heating in the planet's interiors assuming an electrical conductivity profile typical of a hot rocky planet and a moderate stellar magnetic field typical of an old inactive star. Then we use a mantle convection code (CHIC) to simulate the evolution of volcanic outgassing with time. Results. We show that although in most cases volcanic outgassing on HD 3167b is not very significant in the absence of induction heating, including this heating mechanism changes the picture and leads to a substantial increase in the outgassing from the planet's mantle. This result shows that induction heating combined with a high surface temperature is capable of driving volcanism on massive super-Earths, which has important observational implications.
Modeling Volcanic Plume Heights Across Exoplanet Atmospheres: Insights from TRAPPIST-1
NASA Goddard Space Flight Center（美国国家航空航天局戈达德太空飞行中心）；Integrated Space Science and Technology Institute, Department of Physics, American University（美国大学物理系综合空间科学与技术研究所）
Interior redox state effects on the stability of secondary atmospheres and observational manifestations: LP 791-18 d as a case study for outgassing rocky exoplanets
本研究以 LP 791-18 d 为例，耦合内部氧化还原状态与大气过程，揭示氧逸度对大气稳定性和观测特征的控制作用。
The HD 40307 Planetary System: Super-Earths or Mini-Neptunes?
HD 40307有三颗质量小于10个地球质量的行星，这表明这些行星可能是岩石行星。然而，只有径向速度数据，不可能确定这些行星是岩石还是气体。在这里，我们利用系统的各种动力学特征，以评估行星的物理特性。观测允许圆形轨道，但数值积分表明偏心率必须至少为0.0001。此外，行星b和c距离恒星如此之近，潮汐效应非常显著。如果行星b的潮汐参数类似于太阳系中的类地行星，并且剩余离心率大于0.001，那么，回到过去，该系统在恒星的寿命（我们估计为6.1 +/- 1.6 Gyr）内是不稳定的。此外，如果离心率是那么大，而内行星是岩石的，那么它的潮汐加热可能比每单位表面积上的火山岩大一个数量级。如果行星b不是类地行星，例如海王星，这些物理限制就不适用。这一分析表明，这些行星不像地球，更像是我们的巨行星。在这两种情况下，我们发现行星可能是在更大的半径形成的，并在早期（通过磁盘相互作用）迁移到它们目前的轨道。这项研究展示了如何利用系外行星系统的轨道和动力学特性来约束行星的物理特性。
