Current massive-star astrophysics struggles with a number of urgent questions:what are the true mass-loss rates, what is the role of magnetic fields, how areX-rays produced? HD54879 provides an important laboratory to study thesequestions. While a strong magnetic field (2.1,kG) has been recently detected inthis star, it otherwise exhibits a normal spectrum of O9.7 main sequence type.We propose joint XMM and HST observations of HD54879. Analysis of the UVspectrum will establish the parameters of the cool stellar wind, while from theXMM data the hot plasma component will be studied. The new observations willestablish a gauge for stellar wind theory and provide a template X-ray spectrumfor magnetic massive stars with weak wind.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2016-05-01T04:53:57Z/2016-05-01T16:02:17Z
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, Prof Wolf-Rainer Hamann, 2017, 'Joint XMM-Newton and HST study of the magnetic weak-wind O-star HD 54879', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-kxf6te9
