We propose XMM-NEWTON EPIC observations of the prototype of Classical Cepheids,δ Cep, that we discovered is a variable X-ray and FUV emission-line star.The data will complement existing / approved HST FUV spectroscopy and completeX-ray phase coverage for this important star, which shows well-defined phasedchanges of FUV emission line fluxes from hot (10,000 300,000 K) plasmas. Theemissions peak between pulsation phases 0.75 1.05 and likely originate frompulsation-induced shocks. We request two 90 ksec exposures of δ Cep,covering the critical phase range of virgul0.5 1.0, where X-ray emissions shouldpeak. These phases were not previously covered by XMM. The requestedobservations will provide crucial tests of atmospheric heating theories for Cepheids.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2013-06-28T06:11:55Z/2013-07-03T08:00:22Z
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, Prof Edward Guinan, 2014, 'The Secret Lives of Cepheids: Exploring the X-ray Variability of delta Cep', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-amro4ri
