The peculiar star HD191612 has been followed both in the visible and X-rayranges. In the visible domain, this star displays spectacular line profilevariations alternating between two different spectral states (O6-O8) with aperiod of virgul538d. Observations with XMM over half this timescale have revealed anoverluminosity compared to typical O-type stars and some variations, about 30%in flux. However, the origin of the X-rays is still unclear: since a recentstudy unveiled the binarity of the star (with an orbital period of 1540d), acolliding wind phenomenon might contribute to the bright emission. To assess theorigin of the X-ray emission in this peculiar star, an additional observationwith XMM-Newton is needed.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2008-04-02T23:43:13Z/2008-04-03T06:21:47Z
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, Dr Yael Naze, 2009, 'Disentangling the High-Energy sources in the peculiar magnetic star HD191612', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-ginwufm
