We propose to observe the low activity star Altair (HD 187642) with XMM-Newton.With a spectral type of A7 it is the earliest, magnetically active, single late-type star detected by ROSAT and Einstein. At a distance of only 5 pc it is aunique target to study the X-ray properties of late A stars in detail. Altair isknown to be a very fast rotator, however its X-ray luminosity of 2-3x10^27 erg/sis rather low and its L_X/L_bol ratio is the lowest measured in any nearby star.We want to obtain an RGS spectrum that allows to measure the Ne/O abundance in alow activity star, addressing the controversially debated solar and stellar neonabundance.The observation will enable us to investigate the properties ofcoronal plasma in a star with very shallow convection zone for the first time.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2007-10-17T22:51:55Z/2007-11-01T19:56:31Z
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 Jan Robrade, 2008, 'The hottest cool star:Probing the X-ray emission of the low activity star Altair', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-khzl1ll
