enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. 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.

  3. Nebular hypothesis - Wikipedia

    en.wikipedia.org/wiki/Nebular_hypothesis

    A protoplanetary disk forming in the Orion Nebula. The main problem in the physics of accretion disks is the generation of turbulence and the mechanism responsible for the high effective viscosity. [2] The turbulent viscosity is thought to be responsible for the transport of the mass to the central protostar and momentum to the periphery of the ...

  4. Astronomy - Wikipedia

    en.wikipedia.org/wiki/Astronomy

    Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, meteoroids, asteroids, and comets.

  5. 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.

  6. Strömgren sphere - Wikipedia

    en.wikipedia.org/wiki/Strömgren_sphere

    The Rosette Nebula, an example of a Strömgren sphere In theoretical astrophysics , there can be a sphere of ionized hydrogen (H II) around a young star of the spectral classes O or B . The theory was derived by Bengt Strömgren in 1937 and later named Strömgren sphere after him.

  7. Astrochemistry - Wikipedia

    en.wikipedia.org/wiki/Astrochemistry

    Infographic showing the theorized origin of the chemical elements that make up the human body. Astrochemistry is the study of the abundance and reactions of molecules in the universe, and their interaction with radiation. [1]

  8. Star formation - Wikipedia

    en.wikipedia.org/wiki/Star_formation

    The Orion Nebula is an archetypical example of star formation, from the massive, young stars that are shaping the nebula to the pillars of dense gas that may be the homes of budding stars. Key elements of star formation are only available by observing in wavelengths other than the optical.

  9. NGC 6302 - Wikipedia

    en.wikipedia.org/wiki/NGC_6302

    NGC 6302 (also known as the Bug Nebula, Butterfly Nebula, or Caldwell 69) is a bipolar planetary nebula in the constellation Scorpius.The structure in the nebula is among the most complex ever seen in planetary nebulae.