stars

• what factor determines the type of lifecycle a star undergoes

  the size of a star
• what two phases do all stars of the same or greater size than the sun undergo

  protostar phase

  main sequence phase
• what do stars like the sun become at the end of their life cycle

  a black dwarf
• what 2 things can stars much bigger than the sun become at the end of their lifecycle

  neutron star , black hole
• what two phases do stars of similar size of the sun go through between being a main sequence star and a black dwarf

  red giant , white dwarf
• what 2 phases do stars of greater sizethan the sun go through between being a main sequence star and a neutron star/ black hole

  red giant , supernova
• describe the transition of a star from the nebula stage to the main sequence

  the nebula increases in size untl it is pulled in due to its gravity , causing gpe to turn into ke , the collisions between the particles cause this kinetic energy to turn into thermal energy , eventually the nebula will become hot and dense enough to undergo fusion
• what occurs in the stage where a star is a main sequence star

  the fusion in the star releases energy , the energy balances out with the gravitational potential energy leaving the star , the star is in equilibrium therefore it will not collapse due to gravity or expand due to radioactive behaviour , it is stable
• what happens when a star transitions to the red giant phase

  once all of the hydrogen fuel has been used up , the star begins to fuse helium and other larger nuclei , this causes the star to expand and become a red giant
• how does a red giant become a white dwarf

  once all of the reactions have taken place , the stars gravity pulls in all its mass , making a small dense white dwarf , this will eventually turn into a black dwarf once it has cooled
• why are telescopes located outside earths atmosphere

  the earths atmosphere absorbs many electromagnetic waves , making it difficult to detect certain waves , light pollution can make images less clear , telescopes in space can operate in both day and night