When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Stellar atmosphere - Wikipedia

    en.wikipedia.org/wiki/Stellar_atmosphere

    Overview. The stellar atmosphere is divided into several regions of distinct character: The photosphere, which is the atmosphere's lowest and coolest layer, is normally its only visible part. [1] Light escaping from the surface of the star stems from this region and passes through the higher layers. The Sun 's photosphere has a temperature in ...

  3. Atmosphere of Earth - Wikipedia

    en.wikipedia.org/wiki/Atmosphere_of_Earth

    The atmosphere has a mass of about 5.15 × 10 18 kg, [3] three quarters of which is within about 11 km (6.8 mi; 36,000 ft) of the surface. The atmosphere becomes thinner with increasing altitude, with no definite boundary between the atmosphere and outer space. The Kármán line, at 100 km (62 mi) or 1.57% of Earth's radius, is often used as ...

  4. Stellar classification - Wikipedia

    en.wikipedia.org/wiki/Stellar_classification

    In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element ...

  5. Stellar structure - Wikipedia

    en.wikipedia.org/wiki/Stellar_structure

    Stellar structure. Cross-section of the Sun. Stellar structure models describe the internal structure of a star in detail and make predictions about the luminosity, the color and the future evolution of the star. Different classes and ages of stars have different internal structures, reflecting their elemental makeup and energy transport ...

  6. Interstellar medium - Wikipedia

    en.wikipedia.org/wiki/Interstellar_medium

    The interstellar medium is composed of multiple phases distinguished by whether matter is ionic, atomic, or molecular, and the temperature and density of the matter. The interstellar medium is composed primarily of hydrogen, followed by helium with trace amounts of carbon, oxygen, and nitrogen. [1] The thermal pressures of these phases are in ...

  7. Atmosphere - Wikipedia

    en.wikipedia.org/wiki/Atmosphere

    A stellar atmosphere is the outer region of a star, which includes the layers above the opaque photosphere; stars of low temperature might have outer atmospheres containing compound molecules. The atmosphere of Earth is composed of nitrogen (78%), oxygen (21%), argon (0.9%), carbon dioxide (0.04%) and trace gases. [2]

  8. 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.

  9. Solar System - Wikipedia

    en.wikipedia.org/wiki/Solar_System

    The inner Solar System is the region comprising the terrestrial planets and the asteroids. [ 89 ] Composed mainly of silicates and metals, [ 90 ] the objects of the inner Solar System are relatively close to the Sun; the radius of this entire region is less than the distance between the orbits of Jupiter and Saturn.