We propose short timing observations of V407 Vul, and RX J0806.3+2756; uniquebinary systems with the shortest inferred orbital periods known. Both systemsshow secular spin up of their phase-locked X-ray and optical pulsations withrates consistent with orbital evolution driven by gravitational radiationlosses. Phase coherent timing of all current data for these sources isapproaching the level at which the second frequency derivative can be measured.The value of this quantity is an important discriminator for models of the X-rayemission in these objects (Dall.Osso et al. 2007; Deloye & Taam 2006), andfuture, precise constraints on this parameter require simply that the existingtiming baseline continue to be extended with short, annual observations. Here we propose such observations
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2008-10-05T20:54:00Z/2008-11-12T09:36:50Z
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 Tod Strohmayer, 2009, 'Long-term X-ray Timing of Ultra-compact Binaries', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-mm5rdua
