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Ben Zuckerman from the University of California in Los Angeles (USA) together with colleagues found evidence of the presence in the atmosphere of the white dwarf from the congestion of Head that a hundred light years from us, traces... pollution. Contamination is characteristic elements of rocky bodies, such as fragments of asteroids that were extended to a dying superdense star and destroyed with the passage of the Roche limit.
Planets around white dwarfs difficult to detect using standard methods: the disk of stars (blue dot at the bottom) is extremely low relatively common, for example, the Sun (right).
Moreover, by extending the monitoring of all white dwarfs, Mr. Zuckerman found in 50 out of 100 investigated stars traces "asteroid pollution". True, the dwarf of Head promising for future instrumental study, as it is close to the Earth.
As noted astronomer, traces of asteroid fragments near the star - sign of the presence not only of asteroids, the remains of which we observe, but the solid planets, and even the whole planetary system. To test this reasoning astronomers intend to further explore the nearest white-dwarf of Head with the help of telescopes. If all this is true, a substantial part of white dwarfs indirectly can "get" the planetary system. This is important primarily because notice white dwarf planet is very difficult, due to their low luminosity and the same size disk is very tight (and because small) stars.
Meanwhile, with the help of the spectrometer from the Keck Observatory (USA) managed among other items to detect traces of potassium.
In General, when investigating hundreds of white dwarfs, scientists have identified more than 10 heavy elements that do not normally characterized by white dwarfs, which shed its shell at the stage of the red giant, remaining with the nucleus from one only helium and hydrogen. According to Mr. Zuckerman, the presence of elements gives the formation of the gravity of the white dwarf of new debris disks. Their composition, according to General statistics, very close to the list of elements of the earth's crust; this oxygen, silicon, magnesium and iron. They met and relatively exotic: "I didn't even know that scandium in General is a member [of the periodic table]until we discovered it in the atmosphere of one white dwarfs" - says General education gaps Ben Zuckerman.
In his opinion, not less than one quarter of all white dwarfs have debris disks, gather around such stars of their gravity, which gives hope to the study of asteroids outside the Solar system.
Considered the report was presented in January 2013 at the meeting of the American astronomical society.
Based on the materials Space.Com.