EPIC-pn spectra of X-ray deficient yellow giants and supergiants will explorewhy these stars display anomalous coronal behavior compared with cooler giantsonly slightly further advanced in their evolution. Among the class-III objects,the sharp transition in coronal properties on the way to helium flash might becaused by disruption of a fossil magnetosphere by a newly born solar-likedynamo. But, the class-I supergiants are post-flash, and a second deficiencymechanism likely applies, perhaps highly extended chromospheric envelopesobscuring X-rays from submerged magnetic loops. A key discriminator is thecoronal energy distribution, especially the presence of enhanced softabsorption.
Instrument
EMOS1, EMOS2, EPN, RGS1, RGS2
Temporal Coverage
2006-11-24T21:39:49Z/2006-11-25T09:40:29Z
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 Thomas Ayres, 2008, 'Anomalous Coronae of Yellow Giants and Supergiants', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-lezl4jq
