The supersoft X-ray source RX J0439.8-6809 is an extraordinary rareand interesting object: It is either the hottest known pre-white dwarfor an ultra-short period accreting double-degenerate white dwarfbinary. In each case, J0439.8-6809 is an important cornerstone for thetheory of stellar evolution, either post-AGB star evolution or theevolution of close binary systems. We propose to use the unprecedentedX-ray sensitivity of XMM to clarify the nature of this object and todiscern between these two hypotheses. With a 20 ksec XMM observationwe will be able to detect binary orbital variability on minute timescales down to an amplitude of virgul1 percent. The EPIC pn/MOS spectra
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2001-11-01T05:35:11Z/2001-11-01T11:52:05Z
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 Boris Gaensicke, 2003, 'Demystifying the supersoft X-ray binary RXJ0439.8-6809', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-53n3brw
