Astronomy terms starting with C

21 terms

  1. c, speed of light The speed that light travels in a vacuum. It is about 3 x 108 m/s (186,000 miles/s).
  2. Chromosphere 2,500 km thick (1,600 mi) layer of plasma above the Sun’s photosphere. Temperatures range from ~4500 K to 60,000 K (110,000 to 8,000°F).
  3. Closed Universe A universe where the geometry of space closes upon itself like the surface of a sphere.
  4. cluster Clusters are fixed length blocks of bytes that store data for Microsoft operating systems.
  5. Constant of Proportionality When scientists or theoreticians find a mathematical relationship between two quantities, they design an equation, so that, for example, if one quantity…
  6. Convection The movement of matter due to changes in temperature and density. Warm material rises because it is less dense (lighter) and cool material sinks because…
  7. Convective Zone The Sun is made up of different layers. From its center outward, the Sun’s lay­ers include the core, the convective zone, the radiative zone, the…
  8. Core (Kor) the central part of anything, such as the central mass of necrotic matter in a boil.
  9. Corona The outermost layer of the Sun’s outer atmosphere. This halo of ions extends millions of miles into space and consists of a gas that is much thinner…
  10. Coronagraph An instrument designed to study the Sun’s corona by covering the bright disk of the Sun.
  11. Coronal Hole An area of the corona that appears dark when viewed in ultraviolet light. They are usually located around the poles of the Sun, but can occur at other…
  12. Coronal Mass Ejection (CME) A catastrophic expansion of a part of the coronal magnetic field that causes a huge bubble of plasma and magnetic field to erupt from the Sun.
  13. COSMIC Having to do with the universe as a whole.
  14. Cosmic Microwave Backgroun (CMB) Radiation filling the universe, remaining from the early, hot phase. (It is sometimes called the "primal glow.") Today this radiation has cooled to 2.
  15. Cosmic Ray High energy charged particles traveling through interstellar space at nearly the velocity of light. Most are produced in supernova explosions.
  16. Cosmological Constant, Λ The energy density of the smooth vacuum. Eisntein introduced it as a component of the universe but later withdrew it.
  17. Cosmological Principle A principle invoked in cosmology that severely restricts the large variety of possible cosmological theories: On large scales, the Universe is homogeneous…
  18. Cosmology The study of the universe as a whole, of the contents, structure, and evolution of the universe from the beginning of time to the future.
  19. Coupled to Radiation Matter, such as charged particles, that is strongly affected by radiation.
  20. Critical Density The density of matter/energy that would just halt the expansion of the universe. The dividing line between a collapsing and an ever-expandinguniverse.
  21. Curvature of Spacetime According to Einstein's General Theory of Relativity, mass curves space and time.