The stellar winds of B supergiants (SGs) go through a discontinuous jump intheir terminal velocities, mass loss rates, and X-ray emission at spectral typeB1 which is referred to as the bistability of B SG winds. Since wind shocksproduce the X-ray emission and are highly dependent on the stellar windparameters, B SGs provide a natural laboratory to study the relationship betweenthe radiative force, stellar wind, and X-ray emission. Although the drop inX-ray flux appears consistent with theoretical predictions, our AO-3 XMMobservations of 2 B SGs at the jump indicate severe problems with currenttheory. We are requesting 2 additional EPIC observations of B SGs located nearthe bistability jump to determine the extent of these problems.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2005-10-12T09:45:02Z/2005-10-13T05:38:42Z
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 Wayne Waldron, 2006, 'The B Supergiant Bistability-Jump in X-ray Emission', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-06vtsnq
