NASA discovered six small planets BY PERIODIC: NASA discovers
six small planets orbiting around a star similar to Solel discovery allows the development of new methods of deduction of the size and mass of the stars
NASA announced the discovery, thanks to data from the Kepler spacecraft, six small planets orbiting around a star similar to our Sun, and mass which ranged between 2.3 and 13.5 times that of Earth. Recreation
the planets discovered by the observatory NASA's Kepler. AP
planets orbiting in a system called Kepler-11 and has attracted the attention of scientists because it is composed of a large number of small planets and very together. Launched in March 2009, Kepler must collect data and evidence of planets orbiting around stars with average temperature conditions where there may be liquid water and therefore life.
Thanks to data from Kepler, astronomers from the University of California Santa Cruz (UCSC) have analyzed the orbital dynamics of the planetary system and the results appear in the February issue of the journal Nature. To determine size and mass of the planets, the team analyzed the measurements made by NASA's Kepler observatory, which has captured the changing brightness of the star around which planets revolve when passing before him. The photometer sensitive telescope captures this moment interrupted the brightness of the star, which gives scientists clues about the planet's size and mass by measuring its radius. New method
"This is not only an amazing planetary system, but also validates a new and powerful method to measure the masses of the planets," said Daniel Fabrycky from UCSC, who led the analysis of orbital dynamics along with NASA scientist Jack Lissauer. The five inner planets discovered have masses ranging between 2.3 and 13.5 times that of Earth and its orbital periods are less than 50 days, so that orbit within a region, as a model could fit into the orbit of Mercury in our solar system.
The sixth planet is bigger and further, so scientists could determine that it has an orbital period of 118 days, although it could not calculate the mass. "Of the six planets, the more mass can be equivalent to Neptune and Uranus," says Jonathan Fortney, assistant professor of astronomy and astrophysics at the UCSC, who led the work on structure and composition of planets, with students Eric Lopez and Neil Miller. Different
But in the case of smaller mass planets, there is no close comparison as "different from any we have in our solar system," he said. Previously, the detections of planets were still in transit from Earth with powerful telescopes. However, in the case of the Kepler-11 system, the planets are too small and the star is studied, which is at a distance of 2,000 light years, is too weak to be analyzed from Earth. More than 100 planets have been observed in transit by Kepler and other telescopes, but most are gas giants like Jupiter, and almost all systems are on one planet.
density of the planets, derived from the calculation of the mass and radius, gives clues to its composition and how they might have formed. The six planets have a density lower than that of the Earth but, according to Fortney, "it seems that within two might be mostly water, possibly with a thin skin of hydrogen gas and helium at the top, like mini-Neptune.
amazing atmosphere "Those are far less than the density of water, which seems to have a significant atmosphere hydrogen-helium" a fact that the team considered "surprising" because a small hot planet would have difficulty clinging to a light atmosphere. One reason why this system of six planets is so innovative is that it allows scientists to make comparisons between them. "This is really powerful, because we can find out what happened with this whole system," said Fortney.
Since scientists found the first extrasolar planet in 1992 has been confirmed the existence of about 500. This figure may rise to 1,000 if you include the possible planets located a suitable distance from its star to be habitable.