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Astronomy - PHYS 1040 Final Round Two
Terms in this set (17)
Why is it difficult to get a good picture of what our Milky Way galaxy looks like?
1. Dust blocks our view when we look toward the center or in the plane
2. We don't have a star ship to travel outside of it to see it in its entirety
3. It is very large and the edges are far away and faint.
4. We're in the middle of one of its arms, so we have no perspective
What do we use to study our Milky Way Galaxy?
1. Use radio telescopes to see where clouds of hydrogen gas are.
2. Use infrared or microwaves to penetrate the dust
Why do disk stars bob up and down as they orbit the galaxy?
because the gravity of other disk stars pulls them toward the disk
How many stars do we think there are in our Milky Way Galaxy?
Which of these forms of radiation passes most easily through the disk of the Milky Way?
Currently, where are stars born in the Milky Way?
Density waves in the disc spiral arms
The orbits of halo and bulge stars are special because:
their orbits are randomly inclined to the disk of the galaxy
Where would you be most likely to find an ionization nebula?
in the disk
Where are most of the Milky Way's globular clusters found?
in the halo
How long does it take for light to cross the Milky Way?
Around 100,000 years
When we look at a very distant galaxy, billions of light years away, we see it...
When it was younger than now
How did Edwin Hubble first prove that the strange looking spiral nebulae were really distant galaxies?
He used bright Cepheid variables in them to measure their distances
What do we think lies at the center of the Milky Way?
a massive black hole
List in order of increasing distance the "Standard Candle" methods used by astronomers to measure vast distances within our galaxy and the Universe
Radar, Parallax, Main-Sequence, Cepheids, White dwarf supernova
What do we think are the most probably reasons for the 3 different types of galaxies?
1. Different angular momentum in the pre-galactic cloud
2. Collisions between young galaxies after formation
3. Different initial density in the pre-galactic cloud
How long does light from the nearest star (not including the sun) take to reach us?
About 4 years
Which kind of star is most likely to be part of the spheroidal population?
Halo and Bulge stars