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发帖数: 1994 | 1 Dust and the Helix Nebula
Credit: NASA, JPL-Caltech, Kate Su (Steward Obs, U. Arizona) et al.
Explanation: Dust makes this cosmic eye look red. The eerie Spitzer Space
Telescope image shows infrared radiation from the well-studied Helix Nebula
(NGC 7293) a mere 700 light-years away in the constellation Aquarius. The
two light-year diameter shroud of dust and gas around a central white dwarf
has long been considered an excellent example of a planetary nebula,
representing the final stages in the |
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