GT- HD49798 is a sdO6 star in a spectroscopic binary with orbital period 1.55days. In X-rays it has a very soft spectrum and a periodicity at 13 s,indicating that the companion is a magnetized compact object. The proposedobservation will allow to measure the period evolution (and thus distinguishbetween a ns and a wd) and to confirm the NIV absorption edge suggested by ROSATresults. NOTE FOR THE PLANNING: 3 pointings of 5 ksec each are required, in order tocover different phases of the 1.55 day orbit. The choice in the time constraintsform (repeat every 11 hours) is just a possibility: such a tight constraint on the spacing is not required, as far as different phases are sampled.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2002-05-03T11:01:25Z/2002-09-17T17:17:52Z
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 Martin Turner, 2004, 'EPIC Observations of Anomalous X-ray Pulsars', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-xw5vxry
