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 X-ray emitting plasmas mayalso be present. The contention that Cepheids are X-ray sources is furthersupported by their possible detections in the Copernicus archives (using theUCLXE instrument). Also, our recent Chandra observation discovered Polaris to bea soft X-ray source, but possibly contaminated by a nearby, early-mid dF companion.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2008-06-05T14:26:02Z/2008-06-23T17:49:16Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Edward Guinan, 2009, 'The Secret openParX-rayclosePar Lives of Cepheids: Probing the', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-90q1p5g
