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  2. Atomic and molecular astrophysics - Wikipedia

    en.wikipedia.org/wiki/Atomic_and_molecular...

    Atomic physics plays a key role in astrophysics as astronomers' only information about a particular object comes through the light that it emits, and this light arises through atomic transitions. Molecular astrophysics , developed into a rigorous field of investigation by theoretical astrochemist Alexander Dalgarno beginning in 1967, concerns ...

  3. List of interstellar and circumstellar molecules - Wikipedia

    en.wikipedia.org/wiki/List_of_interstellar_and...

    For example, radio astronomy is most sensitive to small linear molecules with a high molecular dipole. [3] The most common molecule in the Universe, H 2 ( molecular hydrogen ), is completely invisible to radio telescopes because it has no dipole; [ 3 ] its electronic transitions are too energetic for optical telescopes, so detection of H 2 ...

  4. Elephant trunk (astronomy) - Wikipedia

    en.wikipedia.org/wiki/Elephant_trunk_(astronomy)

    Elephant trunks (more formally, cold molecular pillars [1]) are a type of interstellar matter formations found in molecular clouds. They are located in the neighborhood of massive O type and B type stars , which, through their intense radiation, can create expanding regions of ionized gas known as H II regions .

  5. Circumstellar dust - Wikipedia

    en.wikipedia.org/wiki/Circumstellar_dust

    Circumstellar dust is cosmic dust around a star.It can be in the form of a spherical shell or a disc, e.g. an accretion disk.Circumstellar dust can be responsible for significant extinction and is usually the source of an infrared excess for stars that have it.

  6. Molecular cloud - Wikipedia

    en.wikipedia.org/wiki/Molecular_cloud

    A molecular cloud, sometimes called a stellar nursery (if star formation is occurring within), is a type of interstellar cloud, the density and size of which permit absorption nebulae, the formation of molecules (most commonly molecular hydrogen, H 2), and the formation of H II regions.

  7. Astrochemistry - Wikipedia

    en.wikipedia.org/wiki/Astrochemistry

    For this reason, molecules and molecular ions which are unstable on Earth can be highly abundant in space, for example the H 3 + ion. Astrochemistry overlaps with astrophysics and nuclear physics in characterizing the nuclear reactions which occur in stars, as well as the structure of stellar interiors.

  8. List of online music databases - Wikipedia

    en.wikipedia.org/wiki/List_of_online_music_databases

    Database Services No. of tracks No. of releases No. of artists Notes License Full free access Encyclopaedia Metallum: A heavy metal encyclopedia with information, complete discography, links, images, and reviews. ~1,900,000 [29] ~265,000 [29] ~102,000 bands, ~535,000 artists [29] Prog Archives: Progressive rock discography and reviews. 63,978 ...

  9. Astrophysics Data System - Wikipedia

    en.wikipedia.org/wiki/Astrophysics_Data_System

    The database initially contained only astronomical references, but has now grown to incorporate three databases, covering astronomy references (including planetary sciences and solar physics), physics references (including instrumentation and geosciences), as well as preprints of scientific papers from arXiv. The astronomy database is by far ...