Term
|
Definition
| Exposed core of a dead star. |
|
|
Term
| small size + star mass = ? |
|
Definition
|
|
Term
| how is the white dwarf star balanced against gravity? |
|
Definition
| by electron degeneracy pressure |
|
|
Term
| why do white dwarfs shine brightly in the X-ray region? |
|
Definition
|
|
Term
| One solar mass star produces a white dwarf made of what? |
|
Definition
|
|
Term
| About how big is a white dwarf star? |
|
Definition
| about the size of the earth |
|
|
Term
| A teaspoon of material from a white dwarf is equal to.. |
|
Definition
| severl tons of weight on Earth |
|
|
Term
| The heavier a white dwarf is, the ________ it becomes. |
|
Definition
|
|
Term
| No white dwarf can have more mass than how many solar masses? |
|
Definition
|
|
Term
| What is the Chandrasekhar Limit? |
|
Definition
| It says that no white dwarf can have more mass than 1.4 solar masses. |
|
|
Term
| how fast would degenerate electrons have to travel to counter gravity? |
|
Definition
| faster than the speed of light. |
|
|
Term
| Can white dwarfs have fusion by themselves? |
|
Definition
|
|
Term
| What system allows for a white dwarf to gain mass by stripping gas from its neighbor? |
|
Definition
|
|
Term
| According to the Conservation of Angular Momentum, material falling in to a white dwarf ____ gains speed as it gets closer |
|
Definition
|
|
Term
| Expain the process of a Novae |
|
Definition
-Hydrogen from neighbour falls to surface
-As it falls it gets hot, and when it hits the surface it gets compressed
-Thin hot layer of hydrogen builds up on the surface of the white dwarf
-when the temperature reaches 10 million K
-BOOM! |
|
|
Term
| Explain the process of a Supernovae |
|
Definition
-A white dwarf can gain mass
-it it's mass approaches 1.4 solar masses, carbon fusion starts
-Fusion takes place everywhere at the same time
-Instantaneous fusion leads to the white dwarf exploding |
|
|
Term
|
Definition
| the remnant of a massive star |
|
|
Term
| The iron core of a Neutron star becomes all________. |
|
Definition
|
|
Term
| Neutron stars are _____ massive than the sun. |
|
Definition
|
|
Term
| How is the neutron star balanced against gravity? |
|
Definition
| by neutron degeneracy pressure |
|
|
Term
|
Definition
at the center of nebulae
... therefore pulsars are neutron stars |
|
|
Term
| Explain the process of the pulsar |
|
Definition
-as the iron core collapses, it has to spin faster
-Collapse pulls magnetic field lines closer together -> very strong magnetic poles
-the poles emit radiation
-If the poles are not aligned with the spin axis, you get a lighthouse effect. |
|
|
Term
| What do pulsars use to power themselves? |
|
Definition
|
|
Term
| as a pulsar emits power, the rate at which it spins at _________ |
|
Definition
|
|
Term
| slowly, over time, the pulses from a pulsar take _______ and _______ to occur |
|
Definition
|
|
Term
| Can neutron stars pull material from it's companion? |
|
Definition
| yes, just as white dwarfs do |
|
|
Term
| how is an accretion disk formed? |
|
Definition
| pulling material from a companion star |
|
|
Term
| stronger ________ allows materials to heat up further |
|
Definition
|
|
Term
| pulsars from X-ray binaries _______ speed, unlike usual pulsars. |
|
Definition
|
|
Term
| describe the process of x-ray bursters |
|
Definition
-the in-falling Hydrogen creates a layer on the star surface
-steady Hydrogen fusion takes place.
-At the base of the layer, Helium builds up and it begins to burn in bursts |
|
|
Term
| What does the term "black hole" refer? |
|
Definition
| refers to the fact that even the speed of light is not fast enough for an object to escape from it |
|
|
Term
| the term "hole" refers to what? |
|
Definition
|
|
Term
| What is the event horizon? |
|
Definition
| the boundary point of being able to escape a black hole and never being able to escape it |
|
|
Term
| what is the Schwarzschild Radius? |
|
Definition
it describes the size of the event horizon
-it depends only on the mass of the object forming the black hole |
|
|
Term
| A black hole formed by a star of 1 solar mass has a radius of 3 kilometers.. so a star of 10 solar masses would form a black hole with a radius of __ kilometers |
|
Definition
|
|
Term
| Once the star has collapsed past the event horizon, it is a ______ _____ |
|
Definition
|
|
Term
| The ______ outside of a black hole is still the same as for the star |
|
Definition
|
|
Term
|
Definition
|
|
Term
| in a black hole, what is the singularity? |
|
Definition
| where all the star mass goes |
|
|
Term
| What two things happen as a clock with blue numbers is pushed into a black hole? |
|
Definition
As the clock is falling:
1. the numbers turn redder the further the clock falls
2. time ticks more slowly the further it falls |
|
|
Term
| What are the tidal effects of a clock that is pushed into a black hole? |
|
Definition
-the further the clock falls, the more it becomes stratched
-it is stretched due to the increasing change in gravity the closer to the event horizon it gets |
|
|
Term
| Describe the clocks experience as it reaches the event horizon |
|
Definition
-from the clocks point of view, nothing about it slows down. It still ticks the same rate as it had outside the hole
-however, upon reaching the event horizon, the clock will feel itself smoothly pass through it
-the observer watching the clock would require a radio telescope to see the numbers and would NEVER see the clock enter the event horizon |
|
|
Term
| How can we find black holes? |
|
Definition
| Most compelling evidence is in binaries, such as Cygnus X-1 where a visible 8 solar mass object is orbiting an invisible 10 solar mass object that emits x-rays. |
|
|
Term
| What is a Gamma Ray Burst? |
|
Definition
| When a star collapses into a black hole. |
|
|
Term
|
Definition
| When a star with 40-100 solar masses collapses into a black hole which lasts longer than 2 seconds. |
|
|
Term
| What is a short duration gamma burst? |
|
Definition
| When a neutron star collapses into a black hole, or when two neutron stars collide. |
|
|
Term
| What are orbital patterns in a galaxy? |
|
Definition
1) Old halo stars orbit in any direction.
2) Disk stars, old and young, orbit within the disk.
3) Old bulge stars orbit very fast around the center. |
|
|
Term
|
Definition
| Protogalactic clouds from the Big Bang condensed down and squished dust into a spinning disk where stars began to form and recycle in the disk. |
|
|
Term
| How much mass does our galaxy have and what does it argue? |
|
Definition
| Our galaxy has a mass of 2 x 10^41kg, and since it doesn't look like there is that much in our galaxy it is possible evidence of dark matter. |
|
|
Term
| When light is reflected by dust it appears to be ____? |
|
Definition
|
|
Term
| When light is reflected by dust it appears to be ____? |
|
Definition
|
|
Term
| When light passes through dust it appears to be ___? |
|
Definition
|
|
Term
| What are thought to be at the center of every galaxy? |
|
Definition
|
|
Term
| What proof is there that black holes are at the center of galaxies? |
|
Definition
| Orbital patterns of stars near the center of the galaxy suggest that they orbit an object 3-4 solar masses yet that mass is squished into about the size of our solar system. |
|
|
Term
| What are the three main shapes of galaxies? |
|
Definition
| Spiral, Elliptical/Spheroidal, and Irregular |
|
|
Term
| How many stars are there in Dwarf Galaxies? |
|
Definition
|
|
Term
| How many stars are there in Giant Galaxies? |
|
Definition
|
|
Term
| Galaxies are generally part of a _____? |
|
Definition
|
|
Term
| How can we make a guide for the evolution of galaxies? |
|
Definition
| By looking at galaxies that are very far away from us because the light we see is old and thus we can make a guide by comparing old galaxies to new ones and tracking their development. |
|
|
Term
| Galaxies have formed in large groups because in the early Universe they had to overcome _______ _________ |
|
Definition
|
|
Term
| Why are galaxies different? |
|
Definition
| Because of protogalactic spin and protogalactic density. |
|
|
Term
| At the center of large clusters of galaxies are huge central dominant galaxies. How did they get to be so big? |
|
Definition
| They consumed their neighbors which makes a stronge case that elliptical galaxy evolution involves galaxy collisions. |
|
|
Term
|
Definition
| When galaxies collide there is huge pressure and very high temperature which leads to the production of stars en masse. Starburst galaxies can produce up to if not more than 100 new stars per year. |
|
|
Term
| Quasars are radio sources that have strong unknown spectral lines and are thought to be...? |
|
Definition
| Active centers of galaxies traveling at up to 17% the speed of light. |
|
|
Term
| What is one theory about the formation of Jets from incoming material into Supermassive Black Holes? |
|
Definition
| One theory is that the Magnetic Fields in the Black Hole sends energy flying out of the Black Hole along Magnetic Field Lines. |
|
|
