British astronomers have for the first time were able to determine the color of exoplanets. With the help of a telescope "Hubble" researchers from Oxford University Conducted a spectral analysis of the stars in the constellation Vulpecula, and where able to calculate the color of the planet orbiting HD 189733 b. Details referring to the still unpublished article for the magazine scientists Astrophysical Journal Letters lead Nature News.
Since the star is too far away, 63 light years from Earth,
it cannot even take a picture with one of the best telescopes today. However, spectrometers, "Hubble" allowed Researchers to obtain two spectra: the moment when the planet is closed for seeing the star, and the moment when it is in the visible region. Comparing these spectra to each other, researchers were able to determine its optical properties, and in particular to the conclusion of its blue color atmosphere.
Paint in blue planet with uninhabited. It belongs to a class of so-called hot Jupiters: Previous observations have shown that HD 189733 b orbits the star in just two days, and its surface is heated to nearly eight hundred degrees Celsius. Blue color scientists explain the presence of a continuous cloud layer in the lower atmosphere; This mechanism is different from that which is responsible for the blue color of the known planets in the solar system.
Clouds reflect all the rays in approximately equal proportions, and if they were in the upper atmosphere, the HD 189733 would have been white. But because of its location at a lower altitude additional light passes through the sodium-rich atmosphere and that absorbs light yellow in color, leaving only the blue rays: a reflective layer of clouds wrapped an additional filter. The land is colored blue because of a liquid ocean, Neptune because of methane in the atmosphere, but HD 189733 is different from all previously known celestial bodies.
Despite the fact that the number of open exoplanets close to a thousand, direct determination of the color of their complicated by long distances and the lack of sufficiently powerful telescopes. Scientists have repeatedly been able to carry out spectral analysis of the atmosphere of exoplanets, highlighting their light from the Star's light, but these studies was conducted in the infrared range, not giving an answer to a question about the color of the celestial body.