Poster Presentation

Formation of Partial Tori of Hydrogen Atoms around Host Stars of Hot Jupiters

Cheng Chen and Wing-Huen Ip

Because of intense heating by the radiation from the central stars, the upper atmospheres of some hot Jupiters like WASP-12b could expand and fill their Roche lobes. Gas escaping through the L1 Lagragian point would stream into the circumstellar regions leading to the formation of a gas ring surrounding the central star. We have set up numerical models to simulate the continuous injection of hydrogen atoms into the circumstellar space by computing their trajectories under the combined effect of stellar radiation pressure, photoionization and charge exchange process with the stellar wind. We will also discuss the various scenarios of star-planet interaction which might shed light on the transit observations.