Chapter 15 Flashcards
What are white dwarfs
They are stars with a similar mass to the sun, they have a surface temperature of about 25,000 Kelvin, and do not have fusion just give off residual heat
What does a white dwarf become
It was once a low mass star, then it became a white dwarf, and then it becomes a black dwarf that emits no visible light
What is a neutron star
It is one possible end state of a supernova explosion
What are pulsars
Radio waves with rapid pulses from outer space
How does the period of the pulsar relate to the density of the object
It is inversely proportional to the square root of the density of the star
What does a short pulse period mean when it comes to an objects density
It means the object is very dense
What did the cause of a pulsar turn out to be
The pulses were caused by the rotation it wasn’t “pulsing”
What happens when the radius of a star decreases in terms of spin speed
Spin increases
What direction do the pulsar waves emit
The powerful magnetic field beams radiation and energy in two opposing directions
How fast do the charged particles get to earth
They get to almost the speed of light and this produces radio emissions along the polar axes
What is gravitational waves
When two objects rapidly orbit each other they generate gravitational waves (like twirling your finger in a pond)
Are gravitational waves strong
No, they are theoretically weak
What do gravitational waves indirectly cause to binary systems
They cause a binary system to lose energy
What are black holes and how do they form
When a high mass star greater than 10M collapses their core gets compresses. The black hole has an escape velocity that exceeds the speed of light.
What gave black holes a mathematical and physical picture
Einsteins theory of relativity
