8 Flashcards
What are the stages of a star similar to the mass of the Sun’s?(6)
Starts as cloud of dust and gas called a nebula. Gravity pulls this dust together to form a protostar. Temperature rises and when high enough, hydrogen nuclei undergo nuclear fusion to form helium nuclei.
Huge amounts of energy is released keeping the core of the star hot.
Now the star is in a long stable period. This is called a main sequence star.
Eventually the hydrogen in the core begins to run out and the force of gravity is larger than the pressure of thermal expansion. The star compresses enough until it is dense and hot enough that the energy created makes the outer layers of it expand.
Finally, it becomes unstable as a Red Giant and ejects its outer layer of dust and gas. What is left behind is a hot dense solid core called a white dwarf.
What are the different stages of a star with mass not of the sun?(3)
After the star is a Red Supergiant becomes unstable, it starts to glow brightly again undergoing more fusion to make heavier elements.
They expand and contract several times as the balance between changes between gravity and thermal expansion.
Finally, they explode in a supernova and leave either a neutron star or black hole.
What are Asteroids?
Lumps of rock and metals that orbit the sun. Usually found in the asteroid belt.
What are Comets?
Lumps of ice and dust that orbit the Sun. Highly elliptical orbits.
Formula for velocity of a galaxy.
Velocity of a galaxy / Speed of light =
Change in wavelength / original wavelength
How does Red-shift support the Big Bang Theory?(3)
When we look at light from distant galaxies, the same patterns of light from the EM spectrum are seem, but at slightly lower frequencies.
There has been a shift toward the red end of the EM spectrum, therefore Red-shift.
This suggests that all the distant galaxies are moving away from us very quickly in all directions, therefore the universe is expanding which can be explained from the Big Bang.
How does CMB radiation support the Big Bang Theory?(3)
Low frequency electromagnetic radiation has been detected from all parts of the universe. This implies that all of the universe was present at a single point.
The short wavelengths of the gamma radiation emitted in the initial explosion are believed to have become stretched due to the expansion of space into longer wavelength microwaves, hence microwave radiation.
What is absolute magnitude and apparent magnitude?(2)
Apparent magnitude is how bright a star looks when viewed from the earth while absolute magnitude is a much fairer and used test for the luminosity of stars.
This is because it is measured by the luminosity from the distance of 32.68 light years rather than from earth.
What is 0 Kelvin in Celsius?
-273 C
What is the Hertz-spring-Russel diagram?(2)
Diagram that shows luminosity against temperature of stars in the universe.
There are four sections to drawing this graph, the main sequence, white dwarfs, giants, supergiants.
