We propose to observe HS0922+1333, one of the rare progenitors of normal polars,accreting from the stellar wind of the companion star. Due to the extremely lowaccretion rate they enable us to observe crucial details of accretion physicswhich are not accessible in polars already accreting via Roche-lobe overflow.The special geometry of HS0922 also provides the opportunity to get anundisturbed view of the companion star in X-rays, and may thus give a clue tothe question of the secondaries being comparable to single active late typestars. HS0922 is therefore an exceptional target for verifying the currentmodels of the accretion regions on compact stars, of magnetic activity on fastlyrotating late-type stars, and of binary evolution.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2008-11-04T06:39:49Z/2008-11-04T19:31:47Z
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, Mr Justus Vogel, 2009, 'The origin of X-rays in the progenitors of polars', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-n2lrfq2
