Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

11 Cards in this Set

  • Front
  • Back
evolutionary track
represents changes in a star's temperature and luminosity on the H-R diagram; not its motion in space
interstellar medium
matter between the stars which contains at least 10% of all the known mass in our Galaxy
reflection nebula
bluish haze around certain stars (ex. Pleiades) caused by fine grains of interstellar dust that efficiently scatter and reflect blue light
interstellar extinction
when dense interstellar clouds dim or completely block the light from the stars behind them
interstellar reddening
when interstellar dust in fron tof a star scatters blue light making the star seem redder than it actually is: different from reddening caused by Doppler shift
Giant Molecular Clouds
concentrated vast amounts of interstellar gas and dust
a violent detonationthat ends the life cycle of a massive star
Nebulae, or supernova remnants
remains of dead stars scattered across the sky
Jeans instability
when a region of a cloud is sufficiently cold and dense, the gravitational attraction of the matter in this region overwhelms the pressure there and pulls the gas together to form a new star
newly formed object before it becomes a star
pre-main-sequence star
what a protostar becomes when mass accretion stops--some protostars that are incredibly massive begin fusing so quickly that they go diretly to the main sequence