Cosmology Flashcards
(11 cards)
What is CMBR?
Cosmic microwave background radiation- after the Big Bang the radiation emitted will have cooled as it spread out in the universe, since it is expanding in it will continue to cool
What is red shift?
The observed wavelength is longer then the emitted wavelength, this occurs because of relative motion away from us.
Name two proofs of the Big Bang
CMBR
Red Shift
How do these prove the Big Bang?
RS - All galaxies are receding, this is evident by the red shift, this is evidence of the expanding universe
CMB - Radiation emitted from the Big Bang could add it spread through the universe and will continue to as the universe keeps expanding. Microwave radiation is detected from all directions, this wavelength is expected from the 2.3k, which temp of universe.
What is the process happening in main sequence stars?
Fruition of H -> He. This releases energy which causes the star to heat up. This causes it to expand.
What is hydrostatic equilibrium?
When the outwards pressure from temperature equals the inward pressure from gravity.
What is a protostar?
Regions of dust and gas.
Describe the life cycle of a star. For high and average mass stars.
Protostar -> Main sequence star -> Red giant -> Planetary nebula -> White dwarf
-> Main sequence star -> Red super giant -> Supernova -> Neutron star/black hole
Describe the process of Protostar -> Main sequence star.
The mass in influence by gravitational force. This causes all of it to accelerate towards the center. The GPE. Is converted into KE, which increases temp in the core. If the temperature and pressure in high enough then the hydrogen fusion can occur.
Requirements for fusion in a star.
High temperature
High pressure
Relationship between wavelength emitted and the surface temperature of star (k).
Wavelength peak X Temperature of surface = 2.9x10^-3
