Stars And Cosmology Flashcards
How heavy are low mass stars?
0.5 Mo - 10 Mo
What stops gravitational collapse in a white dwarf?
Electron Degeneracy Pressure, two electrons can or exist in the same energy state, can support Fromm gravitational collapse a maximum mass of 1.44 Mo, this is the Chandrasekhar limit
In red supergiants there are layers where fusion occurs, where are the heaviest elements found?
In the core (up to iron) then layers of lighter elements near the outer surface
What prevents the nuetron star from collapse?
Nuetron degeneracy pressure ( they cannot occupy the same energy state)
What stars are located at the top of the HR diagram?
Supergiants
What stars are located at the bottom left of the HR diagram?
White Dwarfs
What are absorption spectra?
Some wavelengths of light are absorbed by the gas
What is theta in the diffraction grating equation?
the angle between the central maximum and the order of interest
Red is diffracted….
more than blue (higher wavelength)
What is Weins displacement law?
Maximum llamada is inversely proportional to T (in kelvin)
The peak wavelength corresponds too…
colour ( lower peak wavelength = more blue)
What is Stefans Law?
The total power radiated per unit surface area of a black body is directly proportional to the fourth power of the absolute temperature of the black body
If the object moves away from you then you have…
Red shift
What is the cosmological principle?
The Universe is isotropic and homogeneous
What does homogeneous mean?
Matter is uniformly distributed (the density of the universe is the same everywhere)
