ch16,17,18
most stars are formed about 200 small stars
.08 stellar mass = how many stars:
about 50 stars
.5 stellar mass(Msun)= about how many stars:
white dwarf limit
1.4 solar masses(1.4 Msun) is the:
1 big ass star
150 stellar mass(Msun)= about how many stars:
about 10 large stars
2 stellar mass(Msun)= about how many stars:
super massive black hole(10E9Msun)
a human might survive the event horizon of a :
black hole
after a supernova if gravity can overcome the neutron stars degeneracy pressure then the core will collapse into a:
hydrogen shell fusion
after core shrinks from hydrogen fusion stopping, the hydrogen left around the now helium core will start fusion again in this:
solar wind
after helium fusion begins large amounts of mass will escape the red giant in:
subgiant
after hydrogen fusion stops in a low mass star, it's core begins to shrink, but it's outer layer will expand into a:
gamma ray bursts
are explosions with unimaginable power:
red giant
as the expansion of the outer layers of a low mass star continues the luminosity will increase and will eventually become a :
iron
bad news for stellar core
could be cause of gamma ray burst
binary neutron stars crashing into each other, or one into a black hole could be the cause of these:
cygnus x1 most promising candidate known for being black hole
black hole that binary neutron star with larger size than 3Msun:
carbon fusion
can be reached in high mass stars after helium fusion due to heat beating any sign of degeneracy pressure:
accretion disk
disk of mass for white dwarf companion swirls and becomes this:
infrared light
dust is less effective at blocking_____ making it possible to see stars behind a molecular cloud:
interstellar dust
elements like carbon, silicon, oxygen, and iron are found in tiny, solid grains of:
supernova remnent
expanding cloud of debris from a supernova:
stars Life track stages
formation of protostar, convective contraction, radiative contraction, self sustaining fusion:
interstellar medium
gas and dust found in the spaces between stars
hydrogen, helium, and a few heavier elements
gases in the interstellar medium
gravity forms stars easier
gravity can form stars more easily if something aides it like two molecular clouds colliding:
how stars form
gravity causes a molecular cloud to contract, and the contraction continues until central object becomes hot enough to sustain nuclear fusion in its core:
whens the battle with thermal pressure
gravity is stronger in molecular clouds due to more density (more mass in volume) and due to low temps in molecular clouds gravity does this:
super nova
happens after gravity has crushed away degeneracy pressure and the iron core can no longer resist it, outer layers of star are shot into space:
thermal pulses
helium fusion rates spike during helium shell fusion are:
carbon
helium fusion will result in a _____ core:
photons
how molecular clouds quickly rid themselves of thermal energy build up:
molecular clouds
interstellar clouds where stars are born due to conditions cold and dense enough for atoms to form molecules:
1% of molecular clouds mass
interstellar dust accounts for this percent of the mass of a molecular cloud:
70% hydrogen, 28% helium, 2% heavier elements
interstellar medium contents
neutron star
is the ball of neutrons left behind the when an iron core collapses into a massive super novae, about 10 km in radius with more mass than our sun:
novae
less luminous then super but still pretty darn bright happens on white dwarfs when fusion starts again from accretion of the white dwarf in binary system:
between 2 and 3 solar masses
limit of size for a neutron star:
planetary nebula
low mass stars like the sun will eventually eject their outer layers, the exposed core will still be very hot, radiation will ionize gasses making it grow brightly as a:
1987A
most recently known supernova was in the large Magellanic cloud in this year and so named:
gravity is super strong on a
neutron star
x-ray burst
neutron stars version of white dwarfs novae, but release x-rays:
white dwarf supernovae
occurs when a white dwarf has reached the white dwarf limit(carbon bomb):
gas infall
one way that a protostar gains mass(continues till gas is gone):
protostellar wind
outward flow of particles similar to the solar wind:
gravitational equilibrium
outward push of gas pressure balances the inward pull of gravity:
white dwarfs, then become to cold to emit light
planetary nebula become
event horizon
point of no return for objects entering black hole:
singularity
point where all black hole matter is crushed to single point:
neutron degeneracy pressure
prevents gravity from crushing neutron star:
carbon monoxide
produces radio emission lines allowing the mapping of molecular clouds:
1.0E6 K or one million Kelvin
protostar central temp:
3000 K
protostar surface heats up to this and then remains there until contraction halts:
LIfe of a high mass star
protostar, blue main sequence, red supergiant, hellium core super giant, multiple shell fusion supergiant, supernova, neutron star or black hole.
life of a low mass star
protostar, yellow main sequence, red giant, helium core fusion star, double shell red giant, planetary nebula, white dwarf:
binary system
prototstars can be very close to each other, gravity can cause them to orbit each other due to their angular momentum helping form:
protostellar disk
rapid rotation prevents gas from falling on a protostar and forms this:
pulsars(first known as little Green Men)
rapidly pulsing radio waves in space coming from neutron stars:
helium-capture reaction
reactions in which helium nucleus fuse with other nucleus:
gravitational red shift
red shift in black holes caused by gravity:
oldest stars possible
should consist of only hydrogen, and helium:
interstellar reddening
stars around the edges of molecular clouds are redder because dust blocks blue light better than red, this is referred to as:
intermediate-mass stars
stars born with masses between 2 and 8 solar masses:
high-mass stars
stars born with masses greater than 8 solar masses:
clusters
stars form in large:
low mass stars
stars that are born with less than 2 solar masses (2Msun) of material:
more recent stars
stars with more heavy elements are probably:
crab nebula
still visible supernova remnant:
hypernova
super nova that causes a black hole:
thermal pressure
temperature dependent pressure in ordinary gas clouds:
100 million K
temperature where helium core can start helium fusion:
protostar
the dense center of a molecular cloud fragment(look like stars but not quite hot enough for nuclear fusion):
molecular cloud cores
the dense clumps in a molecular cloud that form stars:
Schwarzschild radius
the radius of the event horizon:
radiation pressure
the reason stars have a maximum mass:
close binary system
these stars no longer have angular momentum, orbital separation is < .1 AU with orbital periods of just a few days:
brown dwarfs
this is a "failed star" due to degeneracy pressure will slowly radiates away its thermal energy cooling with time:
degeneracy pressure
this kind of pressure caused by density prevents objects with masses less than .08Msun from becoming true stars:
10 K-30 K
typical temperature of a molecular cloud:
takes forever to cross event horizon(but actually is squeezed and stretched to oblivion:
view from spaceship if friend jumped into black hole:
iron cant generate any nuclear energy
what element doesn't generate nuclear energy:
neutron star
what is left behind after a super nova:
Algol paradox
when binary stars are born at the same time, the more massive star must have shorter life, mass exchange happens:
helium white dwarfs
when degeneracy pressure prevents the collapse of the helium core before fusion the core will become a:
main sequence star
when protostar internal temp reaches 10E6 K and contraction stops a star of this type is born:
spacetime
when space and time are bundled up together to form a fourth dimension near event horizon:
super dense
white dwarfs are_________, like the amount of mass in the sun in the size of the earth.
more massive(higher gravity compresses them).
white dwarfs that are smaller in size are actually:
protostellar jets
young prototstars fire these high speed streams of gas(usually two in opposite directions):