|Title||Joint XMM-Newton and HST study of the magnetic weak-wind O-star HD 54879|
|Author||Prof Wolf-Rainer Hamann|
|Description||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 are X-rays produced? HD54879 provides an important laboratory to study these questions. While a strong magnetic field (2.1,kG) has been recently detected in this 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 UV spectrum will establish the parameters of the cool stellar wind, while from the XMM data the hot plasma component will be studied. The new observations will establish a gauge for stellar wind theory and provide a template X-ray spectrum for magnetic massive stars with weak wind.|
|Publication||A combined HST and XMM-Newton campaign for the magnetic O9.7 V star HD 54879. Constraining the weak-wind problem of massive stars . Shenar, T., Oskinova, L. M., et all. . A&A . 606-91 . 2017 . 2017A&A...606A..91S ,
A short and sudden increase of the magnetic field strength and the accompanying spectral variability in the O9.7 V star HD 54879 . Hubrig, S., Ku00fcker, M., et all. . MNRAS . 484-4495 . 2019 . 2019MNRAS.484.4495H ,
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2017-05-18T22:00:00Z, 078018, 17.56_20190403_1200. https://doi.org/10.5270/esa-kxf6te9|