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  2. Nebular hypothesis - Wikipedia

    en.wikipedia.org/wiki/Nebular_hypothesis

    Some elements of the original nebular theory are echoed in modern theories of planetary formation, but most elements have been superseded. According to the nebular theory, stars form in massive and dense clouds of molecular hydrogen—giant molecular clouds (GMC). These clouds are gravitationally unstable, and matter coalesces within them to ...

  3. History of Solar System formation and evolution hypotheses

    en.wikipedia.org/wiki/History_of_Solar_System...

    French philosopher and mathematician René Descartes was the first to propose a model for the origin of the Solar System in his book The World, written from 1629 to 1633.. In his view, the universe was filled with vortices of swirling particles, and both the Sun and planets had condensed from a large vortex that had contracted, which he thought could explain the circular motion of the plane

  4. Formation and evolution of the Solar System - Wikipedia

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

    The Ring nebula, a planetary nebula similar to what the Sun will become. This is a relatively peaceful event, nothing akin to a supernova, which the Sun is too small to undergo as part of its evolution. Any observer present to witness this occurrence would see a massive increase in the speed of the solar wind, but not enough to destroy a planet ...

  5. Stellar evolution - Wikipedia

    en.wikipedia.org/wiki/Stellar_evolution

    Representative lifetimes of stars as a function of their masses The change in size with time of a Sun-like star Artist's depiction of the life cycle of a Sun-like star, starting as a main-sequence star at lower left then expanding through the subgiant and giant phases, until its outer envelope is expelled to form a planetary nebula at upper right Chart of stellar evolution

  6. Nebula - Wikipedia

    en.wikipedia.org/wiki/Nebula

    The Westbrook Nebula, a protoplanetary nebula. A protoplanetary nebula or preplanetary nebula [ 27 ] (PPN, plural PPNe) is an astronomical object which is at the short-lived episode during a star 's rapid evolution between the late asymptotic giant branch (LAGB) [a] phase and the subsequent planetary nebula (PN) phase.

  7. A horse-shaped nebula gets its close-up in new photos ... - AOL

    www.aol.com/news/horse-shaped-nebula-gets-close...

    NASA’s Webb Space Telescope has revealed the sharpest images yet of a portion of a horse-shaped nebula, showing the “mane” in finer detail. The Horsehead Nebula, in the constellation Orion ...

  8. 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.

  9. Chamberlin–Moulton planetesimal hypothesis - Wikipedia

    en.wikipedia.org/wiki/Chamberlin–Moulton...

    Their theory proposed that as these objects collided over time, the planets and their moons were built up, with comets and asteroids being the leftover debris. The "spiral nebulae" photographed at Lick Observatory were thought to possibly be views of other suns undergoing this process.