Posts Tagged "Planetary Nebula"


Helix hides Comets in its Core


Posted By on Feb 14, 2007

It is easy in astronomy to lump different objects into specific groups. At the top-most level, there are stars, galaxies, planetary systems (including asteroids and comets), and dust-bunnies interstellar and intergalactic media (clouds and nebula). Looking a bit deeper, each of these categories can be nit-picked apart into more sub-categories. For instance, stars can be divided up by energy generation mechanism, or mass, or both. But,...

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