Physical Science Test 2 Flashcards
(48 cards)
Draw the life cycle of a star
drawing
nebula
gravity begins to pull gases and dust together, temperature remains fairly cold, no fusion yet.
a large cloud of gas and dust spread out over a large volume of space
Ex. Eagle Nevula pillars of creation
protostar
some heat produced, no fusion, gases and dust become more dense especially at center
a contracting cloud of gas and dust with enough mass to form a star
main sequence star
fusion force outward matches gravity inward(equilibrium), sizes and colors of stars vary, 90% of stars are in this stage
red giant and giant
gravity overcomes fusion and compresses the star, to relieve the heat and pressure, the star expands and star cools, light produced is now more dim
supernova
fusion slows down gravity is winning, star collapses, heat build up causes explosion
planetary nebula
gravity continues to win but outer gases leave, core remains, fusion can cause other elements
white dwarf
may have companion star. Can steal hydrogen from companion but takes in too fast causing supernova
black dwarf
all fusion has ended
neutron star
mostly neutrons remain after an explosion, some fusion with helium wich causes pulsating light
black hole
remaining core is so dense that supergravity doesn’t let light escape
what percent of stars are white dwarfs
10%
what percent of stars are giants or supergiants
1%
when is a star formed?
when a contracting cloud of gas and dust becomes so dense and hot that nuclear fusion begins
how is a main sequence star in equilibrium
when it’s outward thermal pressure from fusion and gravity’s inward pull are equal or balancing itself out
list 3 characteristics of a large, young star
- large core
- huge amount of energy
- strong gravity
- bluelish color
why do large stars not last as long as small stars
they use their energy more quickly because they’re so bright, causing them to run out fuel more quickly.
what causes a star to begin dying
it runs out of fuel
how is iron made in high mass stars
when it evolves from hydrogen fusion to fusion of other elements
How did Giovanni Baptista Riccioli discover about Mizar and Alcor
he discovered that they are a binary star system
what is a binary star
a star system with two stars
if one star of a binary star system is dim how do we know its there
by the motion of the other star
what is an eclipsing binary
one star passes in front of the other
what are two differences between an open cluster and a globular cluster
open- disorganized
globular- large group of older star
