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发帖数: 298 | 1 Invisible corona
The stars of the Milky Way's main disk span a region of space about 100,000
light-years across, and the thick central bulge is a sphere about 25,000
light-years in diameter. To picture this, think of a typical sci-fi flying
saucer. For decades, this was the official picture of our galaxy. More
recently, a handful of studies have added a sprinkling of stars that live in
a sparse halo outside the main disk.
Then early this year, astronomers made a remarkable announcement: Our gala |
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