The Secret openParX-rayclosePar Lives of Cepheids: Probing the

In this pilot study, XMM observations of the bright Cepheids Polaris, delta Cep,beta Dor and l Car will solve two important recently uncovered puzzles. FUSEspectra of Polaris and beta Dor display prominent emission lines of C III and OVI from hot plasma with T up to at least virgul500,000 K. Moreover, the presence ofstrong emissions in the FUV (IUE/SWP) spectra of all four targets (C III, C IVand, in some cases, He II) makes a strong case that Xray emitting plasmas mayalso be present. The contention that Cepheids are Xray sources is furthersupported by their possible detections in the Copernicus archives (using theUCLXE instrument). Also, our recent Chandra observation discovered Polaris to bea soft Xray source, but possibly contaminated by a nearby, earlymid dF companion. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]