final practice questions Flashcards
Theoretical upper limit for the mass of a star
150-200 solar masses
How stars orbit in our galaxy
Disk: orbit in the same direction with little vertical motion
Bulge/halo: random orientations
Neutron star limit to create a black hole?
3 Msun
Put these eras in order from least to most recent: Planck Era, Era of Atoms, Particle Era, GUT Era
Planck, GUT, Particle, Atoms
What is a flaw of the original, pre-inflation Big Bang Theory?
Fails to explain large-scale uniformity of the temperature of the universe
What evidence is used to detect potential black holes?
Gravitational waves
Motion of stars and gas nearby
Materials in the surrounding accretion disk fading from view
How would a larger Hubble constant affect our understanding of the age of the universe?
The universe would be younger
How to measure distance from the center of the Milky Way?
Use RR Lyrae variable stars to measure distance to globular clusters
The cause of the first accelerating expansion of the universe
inflation
Why are white dwarf supernovae good standard candles?
They have about the same luminosity due to the Chandrasekhar limit
Difference between a nova and a supernova
Supernovae leave nothing behind; novae leave a white dwarf behind
Where does energy come from in a black hole?
Kinetic energy comes from matter falling into the black hole
What do different colors in the Cosmic Microwave Background represent?
Temperature
What electron degeneracy pressure?
High electron density, high speed of electron movement
What supports white dwarves against the crush of gravity?
Electron degeneracy pressure
Major galaxy types
Spiral
Elliptical
Irregular
Evidence supporting the Big Bang Theory
The universe is expanding
Correctly predicts the abundance of helium and other light elements
Detected leftover thermal radiation from the Big Bang
What percentage of our universe are ordinary matter, dark matter, and dark energy?
4% ordinary matter
22% dark matter
74% dark energy