space physics - life cycle of a star Flashcards
birth (nebula/protostar/main sequence star), death of a small star (red giant/small giant), death of a massive star (super red giant, supernova, neutron star, black hole)
what are the 3 titles of the birth of a star
nebula
protostar
main sequence star
birth: nebula
1 st
cloud of dust and gas particles - originates from the start of the Universe or remnants of planet and star formation
birth: protostar
2nd
particles are drawn together under their own gravity; kinetic energy gained leads to thermonuclear fusion reactions - this starts the main phase
birth: main sequence star
3rd
small hydrogen and helium atoms are fused together, forming larger atoms
helium - carbon - iron
after this, smaller stars will behave differently from massive stars
what are the 2 titles of the death of a small star
red giant
white dwarf
death of a small star: red giant
1st
when almost all of the hydrogen has been used, the star will expand
for example, the sun would engulf the nearest 3 planets
death of a small star: white dwarf
2nd
matter making up most of the red dwarf is distributed to the surroundings; the remainder collapses as a hot, dense mass which will cool and fade - this becomes a black dwarf
what are the 4 titles of the birth of a massive star
super red giant
supernova
neutron star
black hole
death of massive star:
super red giant
like the red giant, just bigger with a denser core (betelgeuse)
death of a massive star:
supernova
star rapidly collapses in a supernova explosion when the hydrogen has run out.
intense heat and pressure will cause further fusion to create the heaviest naturally-occurring elements and distribute them
the larger masses may cluster to form planets
death of a massive star:
neutron star
after supernova - very small, dense, rapidly spinning neutron star may remain
death of a massive star:
black hole
largest stars leave behind a black hole
formed since the heaviest stars have such strong gravitational pull and can trap anything going near it
