Astronomers have assumed that the composition of all galaxies is the same as our own.
But using a new, more powerful instrument on the Keck telescope in Hawaii, researchers have discovered that older galaxies contain twenty times more small dim stars, called red dwarves, than younger galaxies such as our own.
"When one of these galaxies that we now know contain lots and lots of small red stars, it may well be true that the night sky is dotted with these small red stars, glowing like embers, and that might produce a very pretty effect."
Doctor Marek Kukula of the Royal Greenwich Observatory describes what the view from a planet in an older galaxy might be like.
According to Professor Pieter van Dokkum of Yale University, the discovery also increases the estimate of the number of planets in the universe and therefore makes it even more likely that there's life somewhere else in the cosmos.
"There's been particular attention recently to these red dwarf stars. In one galaxy there's about a trillion of these stars and there's hundreds of billions of these galaxies. Even if the planet is quite close to the star, you could have liquid water on the planet, because the star is not as bright as the sun, and so a planet can be a lot closer and still be kind of balmy, rather than scorching hot."
The discovery that there are many more stars means that ouruniverse is a much brighter, more crowded place than we previously thought.
发表于 2011-6-26 16:36
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发表于 2011-7-11 16:33
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