how many earths make up across and fill up the sun?
100 across, 1 million to fill up
about 6000 (5780k)
what is going on in core of sun?
hydrogen fusing helium 200,000km
next above the core 300,000km
third part of sun, above the radiation zone 200,000 km
500 km 'surface' above convection zone- light comes out
corona (solar wind)
1 electron and 1 proton
2 protons and 2 neutrons
cooler temperature and intense magnetic field
definition of star
a glowing ball of gas held together by its gravity and powered by nuclear fusion
what can you find with brightness and distance?
what can you find with luminosity and temp
whats other property of star measurements?
mass and temp
how do you measure mass?
binary using keplers third law
how do you measure temperature(surface)
weins law/ or color spectrum of star
low mass stars
remnants end up being white dwarfs
high mass stars
become neutron stars or black hole
main sequence >10=low mass
neutron or blackhole
brightness from sky
the higher the number in magnitude, the blank the object?
the lower the magnitude number, the black it is
what highest magnitude can we still see cuz of brightness
(luminosity) both stars at the same distance
-cant measure luminosity w/ out distance
radius of star
stefan boltemann's law-the hotter the object, the brighter the energy per unit area x temp^4
type II supernova
death of high mass stars
if the mass if below C.L then the gravitational pull is stuck and turns into a white dwarf. cant compress any further
small hot star --cycle starts over
cool temperature- no fusion in core
fuses helium to carbon
birth of star--hydrogen to helium fusing
still bigger yellow giants
unstable magnetic field
once we have luminosity from HR diagram..
we can find brightness and then distance!
after main sequence star becomes...
steps of star:
1. main sequence
2. red giant
3. yellow giant
4. red giant
5. planetary nebula
gravity and pressure forces must balance out
not normal part of star, white dward and it happens to be w/ binary stars, its pulling materials from other stars, increasing its mass
white dwarf fuses and glows really bright blows material and goes out and then starts over the cycle
type Ia (super nova)
same as nova; explosion can occur when white dwarf is pulling material from other stars
death of a low mass star step of life cycle after red giant such. explosion, then turns to white dwarf
HR DIAGRAM: Y AXIS AND X AXIS
geometric method, luminosity (standard candle)
unstable, pulse-brighter than dimmer
pulse slow- rapidly- near by ones how luminous it was went w/ how fast it pulsed
-how we measure the distance of the dragmatra galaxy (standard candle)
the slower the pulse
the more luminous
increasing in temperature
red giant-sun-white dwarf
have a short life span
upper left corner
middle aged stars
on main sequence
high mass stars