Five of the six planets are crammed tightly in around the Kepler-11 star, with orbits of between just ten and 47 days. That means they're all super hot, but the data suggests they're also made mostly of gas.
Finding six new planets around a single star represents animpressive haul. Nasa is calling it the best find since the firstso-called ‘exoplanet’ was discovered 16 years ago. It might not be the most populated solar system yet found - six or possibly seven planets have been found in a rival system, but it's the nature of this new discovery which is getting the astronomers scratching their heads in wonder.
That's strange, because small hot planets this close in should have been ripped asunder by their parent star in their formative years, say the scientists. One possible explanation is that the planets started out bigger and further out and were slowly dragged into tighter orbits, as part of a contracting belt of dust and asteroids.
发表于 2011-6-26 16:28
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发表于 2011-7-12 12:45
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