Astronomy Chapter 10

Card Set Information

Astronomy Chapter 10
2012-04-17 21:00:03
ASTR 205

Stellar Death- key terms and concepts
Show Answers:

  1. nova
    a sudden brightening of a star making it appear as a new star in the sky. Believed to be associated with eruptions on white swarfs in binary system
  2. supernova
    the explosion of a star in which it increases its brightness by a factor of about a million
  3. degenerate matter
    extremely high-density matter in which pressure no longer depends on temperature caused by quantum mechanical effects
  4. helium flash
    the explosive ignition of helium burning that takes place in some giant stars
  5. planetary nebula
    an expanding shell of gas ejected from a star during the latter stages of its evolutions
  6. open cluster
    a cluster of between 100 and 1000 stars with an open, transparent appearence. The stars are not tightly grouped, and they are usually relatively young and location in the disk of the galaxy
  7. globular cluster
    a star cluster containing 100,000 to 1 million stars in a sphere about 75 ly in diameter. Stars in such clusters are generally old, metal-poor, and found in the spherical component of the galaxy
  8. turnoff point
    the point in an H-R diagram at which a cluster's stars turn off the main sequence and move toward the red giant region revealing the age of the cluster
  9. horizontal branch (H-R diagram)
    in the H-R diagram, stars fusing helium in a shell and evolving back toward the giant region
  10. black dwarf
    the end state of white dwarf star that has cooled to a low temperature
  11. Chandrasekhar limit
    the maximum mass of a white dwarf, about 1.4 solar masses
  12. roche lobe
    the volume of space a star controls gravitionally within a binary system
  13. Roche surface
    the dumbbell-shaped surface that encloses the Roche lobes around a close binary star
  14. angular momentum
    a measure of the tendency of a rotating body to continue spinning
  15. accretion disk
    the whirling disk of gas that forms around a compact object, such as a white dwarf, neutron starm, or black hole, as matter is drawn in.
  16. type II supernova
    a supernova explosion caused by the collapse of a massive star
  17. type I supernova
    a supernova explosion cause by the collapse of a white dwarf from gaining mass in a binary star system
  18. type Ia supernova
    a supernova explosion caused by the collapse of white dwarf
  19. type Ib supernova
    a supernova explosion that is just like a type II supernova except the massive star has lost its atmosphere
  20. synchrotron radiation
    radiation emitted when high-speed electrons move through a magnetic field
  21. supernova remnant
    the expanding shell of gas marking the site of a supernova explosion