Astrophysics and Cosmology Flashcards
1
Q
What is Wein’s law
A
Wavelength peak = 1/Abs Temp
Wavelength x Abs Temperature = constant
2
Q
Define Luminosity
A
total power output from the surface of a star
L= sigma T^4 4piR^2
3
Q
Luminosity of black hole
A
0
4
Q
what radiation do stars emit
A
continuous blackbody
5
Q
does electron move up or down energy levels during emission (excitation or de-excitation)
A
move down and emit a photon
6
Q
does electron move up or down energy levels during absorption (excitation or de-excitation)
A
move up and absorb a photon
7
Q
what is change in energy equal to
A
delta E = hc/wavelength
8
Q
what is cosmological principle
A
the universe is homogenous and isotropic
9
Q
does homogenous mean
A
all matter in the universe is evenly distributed
