P16 - Solar system Flashcards
comets
frozen rocks that move around sun
comets orbit
elliptical shape
- squashed circle
birth of a star
-nebula becomes increasingly concentrated
- clouds merge to forma protostar
- protostar become denser so temp increases
- hot enough = nuclear fusion = brighter star
nebula
-clouds of dust/gas pulled together by gravity
protostar becomes denser meaning
particles speed up more and collide more
- transfers energy from gpe to thermal store
hotter star =
nuclei of H fuse
- releases energy
- gets hotter and brighter
main sequence stars
-radiation from H fusion in core
-main stage of life cycle
fusion in core of main sequence star
- keeps it hot
- continues fusion
- gamma flows out steadily from core in all direction
star is stable when
-forces within are balanced
- equilibrium
forces within a star
- gravity contracts star inwards
-balanced by outward force of radiation from nuclear fusion
(to expand)
when a star runs out of hydrogen nuclei to fuse
reaches end of the main star sequence stage
-core collapses
- other layers swell out
- become red giants
red giants eg
sun
red giant
- helium and other light elements fus in core to form heavier element
red giant - when fusion stops
- its own gravity = collapses in
- as it collapses, it heats up = white dwarf
red giant to
yellow giant to white
white dwarf
hot dense white star
much smaller
white dwarf then
fades out
-goes cold to form black dwarfs
stars bigger than the sun
ends life after main sequence stage
- swell out and become red super giant + collapse
red super giant collapse
-matter in star’s ore compresses the core more and more
- supernova
supernova
explosion
- can outshine a galaxy for weeks
after suprnova
neutron star is formed
- or a black hole
when is a black hole formed
after a supernova
-only if there’s enough mass
light elements
from fusion in stars
-nuclear fusion
red giant fuses
helium and small nuclei = larger nuclei
nuclei larger than iron cannot be formed
as that required too much energy