Searching for X-ray Emission in a Classical Nova Shell

An accreting white dwarf in a cataclysmic binary is expected to experience athermonuclear runaway resulting in a classical nova (CN). Highlyenrichedmaterial ejected at high speeds will shock and heat the surroundingcircumstellar medium. There is, however, very little evidence of diffuse Xrayemission from nova shells, but for a few. We propose here to acquire the firstXray observations of the CN shell IPHASX J210204.7+471015 (a.k.a. J210204)recently discovered around an UX UMa novalike system. The size, distance, andage of J210204 make it ideal for an Xray investigation with XMMNewton. Theproposed EPIC observation will lead us to novel results on the characterisationof the interaction of hydrogenpoor, metalrich ejecta with the circumstellar medium. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]