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  2. Chondrule - Wikipedia

    en.wikipedia.org/wiki/Chondrule

    Chondrules in the chondrite classification Grassland. A millimeter scale is shown. Chondrules in the Carbonaceous Chondrite NWA 13887. A chondrule (from Ancient Greek χόνδρος chondros, grain) is a round grain found in a chondrite. Chondrules form as molten or partially molten droplets in space before being accreted to their parent asteroids.

  3. Primitive achondrite - Wikipedia

    en.wikipedia.org/wiki/Primitive_achondrite

    There are many indicators why some achondrites are deemed primitive. Some contain relic chondrules (e.g. Acapulcoite, Lodranite) and some have oxygen isotope ratios that are similar to chondrites. There are similarities in trace element concentrations between primitive achondrites and chondrites.

  4. Carbonaceous chondrite - Wikipedia

    en.wikipedia.org/wiki/Carbonaceous_chondrite

    Aqueous alteration promotes a composition of hydrous phyllosilicates, magnetite, and olivine crystals occurring in a black matrix, and a possible lack of chondrules. It is thought they have not been heated above 50 °C (122 °F), indicating that they condensed in the cooler outer portion of the solar nebula.

  5. List of astronomical catalogues - Wikipedia

    en.wikipedia.org/wiki/List_of_astronomical...

    Ja — Jacoby (planetary nebulae) (for example: Jacoby 1 at 15:23 / +52°14' in Boötes) JaFu — Jacoby-Fullton (planetary nebulae) JAn — John A. Anderson (double stars) Jc — William Stephen Jacob (double stars) Jef — H.M. Jeffers (double stars) Jn — Jones (planetary nebulae) (for example: Jones 1 at 23:36 / +30°28' in Pegasus)

  6. Caldwell catalogue - Wikipedia

    en.wikipedia.org/wiki/Caldwell_catalogue

    [1] [4] Entries in the catalogue are designated with a "C" and the catalogue number (1 to 109). Unlike objects in the Messier catalogue, which are listed roughly in the order of discovery by Messier and his colleagues, [ 5 ] the Caldwell catalogue is ordered by declination , with C1 being the most northerly and C109 being the most southerly ...

  7. CM chondrite - Wikipedia

    en.wikipedia.org/wiki/CM_chondrite

    While CM chondrules are smaller than average in diameter (~300 micrometer), CO chondrules are exceptionally small (~170 um). [ 31 ] [ 32 ] This may be a survivor bias : consider that the water which dissolves CM chondrules successfully eliminates those which are already small, while those which were large may remain to be observed, though with ...

  8. Accretion (astrophysics) - Wikipedia

    en.wikipedia.org/wiki/Accretion_(astrophysics)

    Chondrules, metal grains, and other components likely formed in the solar nebula. These accreted together to form parent asteroids. These accreted together to form parent asteroids. Some of these bodies subsequently melted, forming metallic cores and olivine -rich mantles ; others were aqueously altered. [ 35 ]

  9. Barnard Catalogue - Wikipedia

    en.wikipedia.org/wiki/Barnard_Catalogue

    The nebulae listed by Barnard have become known as Barnard objects. [2] A 1919 version of the catalogue listed 182 nebulae; [3] by the time of the posthumously published 1927 version, it listed 369. [4] Barnard's niece and assistant Mary Ross Calvert, also an astronomer and astrographer, took an important part in creating the catalogue. [5]