Astrophysics Flashcards
What is a galaxy
A collection of billions of stars
What is the universe
A collection of billions of galaxies
What is our galaxy
The Milky Way
The bigger the mass the bigger the
Gravitational feild strength
What does gravitational force do
Pulls two objects together. (E.g the planets and comets orbit the sun due to gravitational force)
Explain a comets orbit of the sun
Comets have highly elliptical orbits. They move fastest when nearest the sun as there is stronger gravitational force.
Stars colour is related to what
A stars temperature
Evolution of stars of similar mass to the sun 1st stage:
Nebula. A star forms from clouds of dust and gas particles
Evolution or stars with mass similar to the sun 2nd stage:
Main Sequence. This is a stable phase the force of gravity is balanced
Evolution or stars with mass similar to the sun 3rd stage:
Red giant. When all hydrogen is used up, larger nuclei form and expand.
Evolution or stars with mass similar to the sun 4th stage:
White Dwarf. When all reactions are over, a small star begins to contract under the pull of gravity.
Evolution or stars with mass larger than the sun 3rd stage:
Super red giant. When it runs out of nuclei to fuse it collapses due to gravity and explodes
Evolution or stars with mass larger than the sun 4th stage:
Supernova. The explosion that throws hot gas into space
Evolution or stars with mass larger than the sun 5th stage:
A neutron star or a black hole. When exploded depending on the mass at the start of its life, a supernova leaves behind either a neutron star or a black hole
Apparent magnitude
How bright a star appears
