Japanese scientists have discovered a star in the constellation Perseus with the "belt" of silica dust, which could be formed after the destruction of Earth-like planets, said in an article published in the Astrophysical Journal Letters.
A team led by Hideaki Fujiwara (Hideaki Fujiwara) from the Japanese National Astronomical Observatory studied the star HD 15407A - a star of spectral class F, in the constellation Perseus, located at a distance of 180 light years from Earth. It is close to the sun shone on their luminosity and mass, although a few hot and heavier.
The astronomers analyzed data about this star, collected Japanese AKARI infrared telescope and NASA's infrared telescope, "Spitzer." As a result, they found that the star at a distance of one astronomical unit (mean distance from Earth to the Sun) is now a total of up to 100 trillion tons (or one ten-millionth of the mass of the Earth), composed of dust particles measuring about one micron.
Belt "calculated" tracked relatively high for a star of this type of infrared radiation (heat), which gave a particle, "reradiating" visible light of a star in the thermal range.
Scientists are using the spectrometric observations were able to determine the chemical composition of dust. As it turns out, are formed by particles of quartz, ie, silicon oxide SiO2. They are heated from 220 to 320 degrees Celsius.
Silica dust, as they note, is extremely rare in the universe, and the reasons for its presence in such numbers around the star HD 15407A is not yet clear. According to one theory, which suggests a high content of quartz in the crust, are crystal could be formed as a result of collisions of large planetesimals celestial bodies (planets, embryos) in orbit around a star. In other words, there could be a planet that was destroyed by a cosmic catastrophe like the one that led to the formation of Earth's Moon.
It is believed that terrestrial planets are formed from the clot gradually condensed cosmic dust orbiting young stars. The radiation from the star gives energy planetesimals, which in turn, begin to emit it in the infrared. Based on this theory, to observe the planet at an early stage of formation, the researchers directed the team Fujiwara looking for stars, surrounded by disks of dust.
This unusual property of the solar system, according to astronomers, may open new horizons for the study of the mineralogical nature of planets outside our solar system. The evolution of extrasolar planets is one of the fundamental trends in modern astronomy since 1995, when it was discovered the first planet outside the solar system - 51 Pegasi b. Now astronomers have discovered over 750 exoplanets.
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