Abstract—Currently, hot Jupiters have extended gaseous (ionospheric) envelopes extending far beyond the Roche lobe. The envelopes are loosely bound to the planet and are subject to a strong influence by stellar wind fluctuations. Since hot Jupiters are close to the parent star, the magnetic field of the stellar wind is an important factor which defines the structure of their magnetospheres. For a typical hot Jupiter, the velocity of stellar wind plasma flowing around the atmosphere is close to the Alfvén velocity. Thus, fluctuations of the stellar wind parameters (density, velocity, magnetic field) can affect conditions for the formation of the bow shock around a hot Jupiter, such as transforming the flow from sub-Alfvén to super-Alfvén regime and back. The study results of three-dimensional numerical MHD simulations confirm that, in a hot Jupiter’s envelope located near the Alfvén point of the stellar wind, both the disappearance and appearance of a detached shock can occur under the influence of a coronal mass ejection. The study also shows that this process can affect the observational manifestations of a hot Jupiter, including the radiation flux in the spectrum’s hard region.

摘要-目前，热木星的气态（电离层）包裹层已经扩展到远远超出罗氏波瓣。包络线松散地绑在行星上，受到恒星风起伏的强烈影响。由于炽热的木星靠近母恒星，因此恒星风的磁场是决定其磁层结构的重要因素。对于典型的热木星，围绕大气层流动的恒星风等离子体的速度接近Alfvén速度。因此，恒星风参数（密度，速度，磁场）的波动会影响到在热木星周围形成弓形激波的条件，例如将流从次阿尔弗芬状态转换为超级阿尔弗芬状态，然后再返回。三维数值MHD模拟的研究结果证实，在位于恒星风Alfvén点附近的热木星的信封中，在日冕物质抛射的影响下，分离的冲击的消失和出现都可能发生。研究还表明，这一过程会影响木星高温的观测表现，包括光谱硬区的辐射通量。