Also known as: dn.
DN has various meanings in the Science category. Discover the full forms, definitions, and usage contexts of DN in Science.
A dark nebula or absorption nebula is a type of interstellar cloud that is so dense it obscures the light from objects behind it, such as background stars and emission or reflection nebulae. The extinction of the light is caused by interstellar dust grains located in the coldest, densest parts of larger molecular clouds.
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