HD49798 is a unique binary composed of a 13 s pulsator, most likely thefastest-rotating massive white dwarf (1.28 Msun), orbiting the brightest O-typesubdwarf. We recently obtained the first phase-connected timing solution, thatshould be extended over a longer period to unveil the small Pdot variationsexpected in this system. Their study will allow us to confirm the nature of thecompact object, to shed light on the accretion flow geometry and on the magneticfield intensity, and to improve the accuracy on the orbital parameters of thisinteresting post-common envelope and possibly SN Ia progenitor system. Only if anew period measurement is obtained during the AO12 it will be possible to extendthe phase-connection over a long time period with a small requirement on observing time.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2013-11-09T18:51:50Z/2013-11-10T06:11:50Z
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, 2014, '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-c1wq4nl
