2. 外语
  3. Hotter and more massive than the Sun, stars called “stragglers” are puzzling to astronomers because such rapidly burning stars w

Hotter and more massive than the Sun, stars called “stragglers” are puzzling to astronomers because such rapidly burning stars w

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问题     Hotter and more massive than the Sun, stars called “stragglers” are puzzling to astronomers because such rapidly burning stars would not be expected to persist in ancient star clusters. Some researchers believe that the typical blue stragglers formed when two ancient, lower-mass stars collide and merge form more massive, hotter star. Peter Leonard theorizes alternatively that in low density globular clusters, where mergers between single stars occur too infrequently to account for the observed quantity of blue stragglers, these stragglers are created instead by a group of stars. He suggests that a pair of stars already orbiting each other presents a larger target for a third star or another pair. Once this new grouping forms, close encounters between the stars could prompt any two to merge as a blue straggler. Leonard’s model predicts that each blue straggler has a distant orbiting companion—as appears true of many blue stragglers in the M67 cluster of the Milky Way galaxy.
Information presented in the passage suggests which of the following about blue stragglers?
选项 A、They originate from stars that are hotter and more massive than the Sun.
B、They are burning more rapidly than other types of stars observed in ancient star clusters.
C、They are older than most other types of stars within the same star cluster.
D、They are less numerous in low-density globular clusters than are pairs of stars.
E、They generally originate from the oldest stars among those found in ancient star clusters.
答案B
解析 由第一句可知，正是因为蓝色游离星比其他古老星团的恒星燃烧更快，这才引起了天文学家的困惑。因此选项B正确。
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