094059

We will use XMM in concert with JWST/MIRI to characterize the impact of XUVradiation on the chemical composition of the hot H/He-rich atmosphere of HD106315c orbiting a bright F5V star in a 21.06-day orbit. MIRI will probe viaSO2 the planetary atmosphere???s sulfur reservoir to verify the impact of XUVradiation on the upper-atmosphere chemical composition. Also XMM will quantifythe X-ray and UV broad-band fluxes impinging on the atmosphere that are r^antfor atmospheric heating and loss. These observations are crucial to understandthe different effects of planet formation atmospheric loss and photochemistryon the upper-atmosphere chemical composition of this Super-Neptune-mass planetand augment a small but important dataset of exoplanets having both JWST and XUV data. [truncated! Please see actual data for full text]