1What do all stars emit?
A continuous spectrum of electromagnetic radiation that comes from surface of a star
2What is a black body?
A body that absorbs all incoming radiation
3What is NOT a black body but can be approximated as one accurately?
A star
4What is the continuous spectrum that a star emits?
A black body spectrum
5What is a black body spectrum?
Spectrum of radiation emitted from a black body at a given surface temp
6What does Weins Displacement Law state?
Peak wavelength of black body spectrum is inversely proportional to the absolute temp (K)
7What is the peak wavelength?
Highest intensity
8What is the Weins law equation?
λmax= b / T
(b=weins constant)
9What does Stefans law state?
Power per unit area emitted by black body in radiation=proportional to its temp to the fourth power
10What is Stefans law equation?
L=δAT^4
(δ=Stefans constant)
11What does the inverse square law state?
Intensity of radiation recieved from a star is inversely proportional to squared distance away from it
12What happens when you increase your distance away from a star?
The total area over which the radiation is spread increases with the square of that distance
13What happens when emitted radiation is spread out over larger area?
The intensity falls
14What is 4πr^2?
Surface area of sphere
15What can you use to find out properties of some stars? What can you find?
The 3 laws together
Luminosity, size, temp, distance
16How can you find luminosity? Which laws?
Need to know the distance of the star from you
Inverse square law used
17How can you find surface temp? Which laws?
Measure black body spec, find peak wavelength of emission
Weins law used
18How can you find size? Which laws?
Need to know luminosity and temp
Stefans law used
19How can you find distance? Which laws?
Need to know radius, temp and luminosity
Measure intensity from earth and use inverse square law
20What does studying stars outside of the visible light spectrum do?
Gives more info about process which took place