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  2. Accretion (astrophysics) - Wikipedia

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

    The initial collapse of a solar-mass protostellar nebula takes around 100,000 years. [ 8 ] [ 9 ] Every nebula begins with a certain amount of angular momentum . Gas in the central part of the nebula, with relatively low angular momentum, undergoes fast compression and forms a hot hydrostatic (non-contracting) core containing a small fraction of ...

  3. 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 ...

  4. Chondrule - Wikipedia

    en.wikipedia.org/wiki/Chondrule

    However, the environmental setting, the energy source for the heating, and the precursor material are not known. The solar nebula or a protoplanetary environment are possible places of formation. Proposed heating mechanisms are: Impacts between molten planetesimals; Meteor ablation; Hot inner nebula; FU Orionis-type outburst of the early sun

  5. Formation and evolution of the Solar System - Wikipedia

    en.wikipedia.org/wiki/Formation_and_evolution_of...

    The various planets are thought to have formed from the solar nebula, the disc-shaped cloud of gas and dust left over from the Sun's formation. [36] The currently accepted method by which the planets formed is accretion, in which the planets began as dust grains in orbit around the central protostar.

  6. Frost line (astrophysics) - Wikipedia

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

    In astronomy or planetary science, the frost line, also known as the snow line or ice line, is the minimum distance from the central protostar of a solar nebula where the temperature is low enough for volatile compounds such as water, ammonia, methane, carbon dioxide and carbon monoxide to condense into solid grains, which will allow their accretion into planetesimals.

  7. Protoplanetary disk - Wikipedia

    en.wikipedia.org/wiki/Protoplanetary_disk

    As this collapsing cloud, called a solar nebula, becomes denser, random gas motions originally present in the cloud average out in favor of the direction of the nebula's net angular momentum. Conservation of angular momentum causes the rotation to increase as the nebula radius decreases. This rotation causes the cloud to flatten out—much like ...

  8. Stellar evolution - Wikipedia

    en.wikipedia.org/wiki/Stellar_evolution

    A protostar continues to grow by accretion of gas and dust from the molecular cloud, becoming a pre-main-sequence star as it reaches its final mass. Further development is determined by its mass. Mass is typically compared to the mass of the Sun: 1.0 M ☉ (2.0 × 10 30 kg) means 1 solar mass.

  9. Early Earth - Wikipedia

    en.wikipedia.org/wiki/Early_Earth

    This period of Earth's history involved the planet's formation from the solar nebula via a process known as accretion. This time period included intense meteorite bombardment as well as giant impacts, including the Moon-forming impact, which resulted in a series of magma oceans and episodes of core formation. [4]