Detection of extrasolar planets discovered.

Scientists used the Hubble telescope to a planet outside our solar system, understanding the chemical composition of its atmosphere, which is to find planets similar to Earth offers a new hope. ."The universe is infinite, in which all the world is countless." Bruno wrote these words after a long period of time, people cherished identity for this statement, but take no real observational evidence. .In the universe there are countless stars, for whom there should be a large number of planets. .Observing planets, but much more difficult than the observed stars. .The size of planets much smaller than stars, more crucially, the planet does not emit light, the conventional observation methods - mainly observed optical band - hard work. .In fact, even the largest diameter of the telescope can not directly take pictures of planets outside the solar system. .The extraterrestrial civilization - if there is one - is only likely to live on the planet, rather than the hot stellar surface. .So, how to find the world outside our solar system? .Capture the shadow of the planet outside the solar system planets always showed any clues. .Not directly observed, there are indirect means. .We know that planets around the star running because of the role of gravity. .We can feel the earth between the sun and the earth the effects of gravity, that is, the earth around the sun each week. .But we rarely notice the role of the Earth to the sun. .Strictly speaking, "the earth around the sun" is a rough argument. .Correct to say that the earth - and all solar system objects - around the solar system's mass center. .A more clear example is the binary. .When people describe the binary stars tend to say two children running around a common center of mass, rather than which one as the dominant star. .Sometimes this concept will help astronomers busy. .People used to think that there is no companion star Sirius, the means of observation was not taken to the Sirius companion photos. .But the scientists found that the background of Sirius in the sky move in the way the wavy lines. .One explanation is that Sirius has a quality not too small "invisible" partners, they bypass each other, so Sirius will be such a strange trajectory. .Later, by means of more powerful telescopes, has finally taken to the companion star Sirius photos - it is a white dwarf made a faint light. .In 1995, when the concept of looking for the help of several scientists brown dwarf (a class of quality rather small, almost non-luminous stars), they observed spectrum of distant stars. .If the brown dwarf star with a partner, in the opinion of scientists on Earth, the star will be slightly to "shake." .Manifested in the spectrum, due to the Doppler effect, the star of the spectral red shift will occur periodically and the blue shift. .In this way, they found the star 51 Pegasi has a brown dwarf may be, but after careful calculations, they found something unthinkable: sinking, the quality of the brown dwarf is too small - only about half of Jupiter. .The final conclusion is that Pegasus has 51 partners, not a star, but a planet. .The discovery of this unusual passion to mobilize the people, only 6 years later, there are already more than 70 such planets have been pulled out. .Three and a half, that is, this year, despite the effective indirect means, but not satisfactory. .We can only know where a planet, it is roughly the number of orbital parameters, what is the nature of the star (so far found most of the gaseous planets like Jupiter.) .In 1999, scientists found that the one called Pegasus star hd 209458 has a planet. .The quality is about the planet Jupiter, 70% to around 3.5 days per week operation of the crazy speed of the star running (of course, it is very near from the stars, so that the surface temperature of 1,000 degrees Celsius, this is something) .. .The planet has a nature, that is, the observer's point of view from the Earth, every 3.5 days it will fly over the surface of hd 209458, which is called "transit" phenomenon. .We know that when a continuous spectrum (for example, is a continuous spectrum of sunlight, that is contained within a certain range of frequency continuous wave) when the gas through the cooler, the gas will be absorbed in the part of the elements of a particular frequency? </ .p>.