8 ASTROPHYSICS Flashcards
Unit for mass
Kilogram (kg)
Unit for distance
Metre (m)
Unit for speed
Metre/second (m/s)
Unit for acceleration
Metre/second [squared] (m/s[squared])
Unit for force
Newton (N)
Unit for time
Second (s)
Unit for gravitational field strength
Newton/kilogram (N/kg)
Define a universe
A large collection of billions of galaxies
Define a galaxy
A large collection of billions of stars
What galaxy is our solar system in
The Milky Way
In terms of g, what happens when the mass of a plant increases
g increases
What do artificial comets orbit
Earth
What do comets orbit
Sun
What does moons orbit
Planets
What do planets orbit
Stars
Shape of planet, artificial comet and moon orbit
Circular
Shape of comet orbit
Highly eliptical
Orbital speed word equation
Orbital speed = 2 x pi x orbital radius / time period
Orbital speed symbol equation
V = 2 pi r / T
First stage of all stars
- Nebula
- Star formed when nucleur fusion occurs
Second stage of all stars
- Main sequence star
- Stable
1st stage of massive star
Becomes a red supergiant
2nd stage of massive star
Explodes due to high energy causing a supernova
1st stage of regular star
Red giant
2nd stage of regular star
Star sheds outer layers becoming white dwarf
Where are red giants on an HR diagram
Top right
Where are red giants on a HR diagram
Top right
Where are white dwarfs on a HR diagram
Bottom left
Where is the main sequence stars on a HR diagram
Top left to bottom right, with flat area in middle
What is on the vertical axis of a HR diagram
Luminocity
What is on the horizontal axis of an HR diagram
Temperature (from hot to cold)
What colour are hot stars
Blue / White
What colour are cold stars
Yellow
Define absoloute magnitude
The measure of a star’s luminocity, at a standard distance
How does red shift OF GALAXIES provide evidence for the big bang theory
- Further from earth = greater red shift
- Larger redshift means faster movement of galaxies
- Further away = faster movement
- Moving apart implies universe was together at some point
How does CMB radiation provide evidence for the big bang theory
- CMBR is same in all directions
- Implies universe was together long time ago
- Wavelength increased as universe expanded
- Universe was hotter long ago
Cosmology wavelength word equation
Change in wavelength / Referance Wavelength = Velocity of galaxy / Speed of light
