Where a white dwarf is in a close binary is a ______.
Norae (Stellar Explosion)
What happens in a Type 1 Supernovae?
- White dwarf in a binary (again.)
- Mass transfer until >1.4 solar mass
- Rapid collapse
Describe the mass and temperature in a Type 2 Supernovae.
- Mass > 8 solar masses
- Temperature > 1010 K
What are some characteristics of Pulsars?
- Rapid and very regular pulse period
- Found in disk of our galaxy
- Whear star-like object
What is the theory of Pulsars?
Dense objects can oscillate, rotate, and revolve rapidly
What are some predictions of relative motion?
- Lengths contract
- Time intervals increase
- Masses increase
Describe General Relativity.
- no more restriction to constant velocities
- a "new look at gravity"
- Mass distorts the geometry of space
What are the four tests for verifying General Relativity?
- Mercury's orbit
- Distortion of star positions near eclipsed sun
- Gravitational Redshift
- Energy loss to gravitational waves
A dark star of more than 7 solar masses, _____.
cannot be a white dwarf or neutron star
What happens around a black hole?
- Supergiant fills its Roch lobe and loses mass
- Infalling mass in 4-million km whirlpool around black hole
Describe the Milky Way's size and shape.
- Diameter: 160,000 LY
- Thickness: 1,000 LY
How long does it take to make one orbit of a Galactic Rotation?
230 Million years
What are some "Dark Matter Candidates"?
- Dead Stars- White dwarfs, neutron stars, black holes
- Brown dwarfs-objects too small to be stars
- Asteroid-size matter
Population I in the galaxy. What is in it?
- Gas and Dust
- Reproessed Elements
Population II. What is in it?
- No Gas and Dust
- Primitive Elements
Spiral arms can be traced by finding ____.
- Young stars
- Gas and Dust
- Older stars NOT concentrated in the arms
What is the Spiral Structure Theory?
- Waves are spiral density waves
- Differential rotation
- Influence of fresh, massive stars
- Influence of nearby galaxies (tides)
Why is the Galactic center not seen at visible and UV wavelengths?
What do Infared, radio, and x-ray observations show?
- Greater star density
- Radio-emitter SgrA
- High speed rotating disk of a few per radius
- x-ray emission
Galaxy type determined by ______.
- Density (star formation rate)
- Angular momentum (spin)
- Interactions with neighbors
What indicates distance in galaxies?
What gives radial velocity in motion of galaxies?
What are the resilts of the mass of Galaxies?
- Spirials: 1011 - 1012 M
- Ellipticals: 106 - 1013 M