HD 49798 is a unique X-ray binary composed of a 13.2 s pulsator, most likely thefastest-rotating massive white dwarf (1.28+/-0.05 solar masses), orbiting thebrightest subdwarf of O spectral type. We obtained a phase-connected timingsolution, that should now be extended over a longer time period to unveil thesmall variations in the spin period expected in this system. Their study willallow us to unambiguously confirm the nature of the compact object, to shedlight on the accretion flow geometry and on the magnetic field intensity. Thisis an updated version of a similar proposal accepted in C priority in AO12.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2014-10-18T07:55:25Z/2014-10-18T17:05:25Z
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 Sandro MEREGHETTI, 2015, 'Toward a long-term phase-connected ephemeris for the unique X-ray binary HD49798', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-n4ixfjc
