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  2. Nebula - Wikipedia

    en.wikipedia.org/wiki/Nebula

    As a result, these nebulae are incredibly faint, taking hours of exposure to capture. These nebulae clouds, an important component of the interstellar medium, are composed of dust particles, hydrogen and carbon monoxide and other elements." [22] They are particularly prominent in the direction of both the north and south celestial poles. The ...

  3. Nebulium - Wikipedia

    en.wikipedia.org/wiki/Nebulium

    Cat's Eye Nebula (NGC 6543) Cat's Eye Nebula (NGC 6543) Nebulium was a proposed element found in astronomical observation of a nebula by William Huggins in 1864. The strong green emission lines of the Cat's Eye Nebula, discovered using spectroscopy, led to the postulation that an as yet unknown element was responsible for this emission.

  4. Dark nebula - Wikipedia

    en.wikipedia.org/wiki/Dark_nebula

    A dark nebula or absorption nebula is a type of interstellar cloud, particularly molecular clouds, that is so dense that it obscures the visible wavelengths of light from objects behind it, such as background stars and emission or reflection nebulae.

  5. Nebular hypothesis - Wikipedia

    en.wikipedia.org/wiki/Nebular_hypothesis

    The cores range in mass from a fraction to several times that of the Sun and are called protostellar (protosolar) nebulae. [2] They possess diameters of 0.01–0.1 pc (2,000–20,000 AU) and a particle number density of roughly 10,000 to 100,000 cm −3. [a] [35] [37] The initial collapse of a solar-mass protostellar nebula takes around 100,000 ...

  6. Cosmic dust - Wikipedia

    en.wikipedia.org/wiki/Cosmic_dust

    The materials in a single interplanetary dust particle often show that the grain elements formed in different locations and at different times in the solar nebula. Most of the matter present in the original solar nebula has since disappeared; drawn into the Sun, expelled into interstellar space, or reprocessed, for example, as part of the ...

  7. Cosmochemistry - Wikipedia

    en.wikipedia.org/wiki/Cosmochemistry

    Meteorites are often studied as part of cosmochemistry. Cosmochemistry (from Ancient Greek κόσμος (kósmos) 'universe' and χημεία (khēmeía) 'chemistry') or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. [1]

  8. Bok globule - Wikipedia

    en.wikipedia.org/wiki/Bok_globule

    In astronomy, Bok globules are isolated and relatively small dark nebulae containing dense cosmic dust and gas from which star formation may take place. Bok globules are found within H II regions, and typically have a mass of about two [1] to 50 solar masses contained within a region about a light year or so across (about 4.5 × 10 47 m 3). [2]

  9. Emission nebula - Wikipedia

    en.wikipedia.org/wiki/Emission_nebula

    Most emission nebulae are about 90% hydrogen, with the remaining helium, oxygen, nitrogen, and other elements. Some of the most prominent emission nebulae visible from the northern celestial hemisphere are the North America Nebula (NGC 7000) and Veil Nebula NGC 6960/6992 in Cygnus , while in the south celestial hemisphere, the Lagoon Nebula M8 ...