Astrophysics Flashcards
What is the universe composed of?
A large collection of billions of galaxies
What is a galaxy?
A large collection of billions of stars
Which galaxy is our solar system located in?
The Milky Way galaxy
How can stars be classified?
According to their colour and temperature
What is a star’s colour related to?
Its surface temperature, hotter stars appear blue, while cooler stars appear red
What does absolute magnitude represent?
The brightness of a star at a standard distance (10 parsecs)
What theory describes the past evolution of the universe?
The Big Bang theory
What are two pieces of evidence supporting the Big Bang theory?
Red-shift and cosmic microwave background (CMB) radiation
Explain the Doppler Effect
The change in observed frequency and wavelength of a wave when its source is moving relative to an observer?
Why does the red-shift of galaxies provide evidence for the expansion of the universe?
It shows that galaxies are moving away from us
What causes moons and artificial satellites to orbit planets?
Gravitational force
What is the equation for the doppler shift
delta - delta o/ delta o = v/c
What is the equation for orbital speed
Orbital speed = 2x (pie) x orbital radius
time period
Explain star sequence order of events Key terms
Nebula –> Protostar –> Star –> Main sequence star –> Red giant / Red supergiant. Red giant –> White dwarf. Red supergiant –> Supernova –> Neutron star / Black hole
