Science:Chapter four section 3: lives of stars
stars can live up until
200 billion years
1c How is a protostar different from a star.
A protostar is a contracting cloud of gas and dust with enough mass to form a star while a star is made up of large amount of gas and relatively small volume.
2a What factor determines how long a star lives?
A star's life is determined by a stars mass.
3a What is a white dwarf? How is it different from a neutron star?
A white dwarf is the blue-white hot core of a star that is left behind cools while a neutron star is the remains of high mass stars after a supernova.
1a What is nebula?
It is a large cloud of dust and gas spread out in an immense volume.
Star
Made up of large amount of gas and relatively small volume
3b Why do some stars become white dwarfs and others become neutron stars or black holes.
Stars because of the gravity become neutron or black holes with more mass while stars with less mass become white dwarfs.
2b A star is twice as massive as the sun. Will its lifespan be longer, shorter, or the same as that of the sun.
The lifespan will be shorter from the sun because the bigger the mass of the star, the shorter the lifespan.
supergiants
The most luminous, most masive stars,with diameters greater than 100 times the diameter of the sun.
3c What will happen to the sun when it runs out of fuel.
The sun, because it is a medium-mass star will either turn into a neutron or black holes because it has enough mass for those while it has too much mass to become a white dwarf.
1b How how does a star form from a nebula?
When the contracting gas and dust from nebula become so dense and hot that nuclear fusion starts.
When is a star born?
When the contracting gas and dust from nebula become so dense and hot that nuclear fusion starts.
Protostar
a contracting cloud of gas and dust with enough mass to form a star
black dwarf
after years, white dwarf eventually fades and becomes a black dwarf
red giant
as low mass stars run out of fuel, their outer layers expand and becom red giants
jocelyn bell
british astonomer detected radio waves and thought it was LGM or little green men. soon they realized it was actually a rapidly spinning nuetron star.
supernova
high mass stars quickly evolve to supergiants. when supergiant runs out of fuel, it can explode suddenly.the explosion is called supernova.
when a star begins to run out of fuel
its core shrinks and it outer portion expands and it becomes a white dwarf, a nuetron star, or a black whole.
Nebula
large cloud of dust and gas spread out in an immense volume. comes form low mass stars turn to red giants and the outer parts still grow and drift out into space(gas cloudthe remains of high mass stars after a supernova.
stars with more mass
last shorter than stars with less mass
How long a star lives depends on its
mass
sun is a mass star
medium
pulsars
spinning neutron stars. some spin 100 times per second!
White dwarf
the blue-white hot core of a star that is left behind cools. only about size of the sun. no fuel. much more dense than sun.
Nuclear fusion
the combination of the nuclei of small atoms to form a larger nucleus; releases energy
Black wholes
the most massive star may become black wholes when they die. a black whole is and object so strong, not even light can escape it.
nuetron stars
the remains of high mass stars after a supernova. smaller and denser than white dwarfs. it is denser than the sun but can be the size of a city
