A-type stars are not expected to be sites of vigorous stellar magnetic activityphenomena like chromospheric or coronal emissions and hence should be X-raydark. With a few exceptions, this expectation is borne out in observations.However, in investigating those A-type stars with X-ray emission where alower-mass companion is not to blame, we have discovered a tentative connectionbetween the presence of near-infrared excess emission (indicating very close-inorbiting dust) and detected X-ray emission. In this proposal we seek to furthervet this with XMM-Newton observations that will yield a statistical sample ofX-ray characterized A-type stars with and without near-infrared excess emission.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2019-05-24T22:39:12Z/2019-10-29T10:17:14Z
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 Carl Melis, 2020, 'Coronae of A-type Stars\: Does Dust Play a RolequestionMark', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-1bm7vqv
