|Title||Anomalous Coronae of Yellow Giants and Supergiants|
|Author||Dr Thomas Ayres|
|Description||EPIC-pn spectra of "X-ray deficient" yellow giants and supergiants will explore why these stars display anomalous coronal behavior compared with cooler giants only slightly further advanced in their evolution. Among the class-III objects, the sharp transition in coronal properties on the way to helium flash might be caused by disruption of a "fossil" magnetosphere by a newly born solar-like dynamo. But, the class-I supergiants are post-flash, and a second deficiency mechanism likely applies, perhaps highly extended chromospheric envelopes obscuring X-rays from submerged magnetic loops. A key discriminator is the coronal energy distribution, especially the presence of enhanced soft absorption.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2008-01-04T00:00:00Z, 040118, 17.56_20190403_1200. https://doi.org/10.5270/esa-lezl4jq|