|Title||A White Dwarf Accreting Asteroids|
|Author||Dr Michael Muno|
|Description||We propose to observe the isolated white dwarf GD 362 (D=25 pc) to search for X-ray emission from the accretion of circumstellar material. Most isolated white dwarfs have atmospheres that are either pure H or He, but GD 362 also exhibits strong metal lines, even though metals should settle out of the photosphere in only a few years. In the last year, GD 362 was discovered to exhibit excess infrared emission from orbiting dust that may have been produced by the tidal disruption of an asteroid. Accretion from this dust can account for the atmospheric metals, and would produce at least 0.5e28 erg-s in X-rays. A measurement of the flux and spectrum of X-rays is needed to confirm the accretion hypothesis, and determine how much H is accreted with the metals.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2007-10-08T00:00:00Z, 040350, 17.56_20190403_1200. https://doi.org/10.5270/esa-07d1t6r|