Astronomy Test 1 Cards Flashcards
What were the two major pieces of evidence that were used discussed to support the Big Bang Theory?
The Universe is Expanding
- Red Shift
- Hubble’s Constant
Cosmic background
-Left over energy from the Big Bang explosion
What method do we use to classify galaxies?
Hubble’s classification system (uses shapes)
List 3 facts about Irregular shaped galaxies.
- An irregular collection of matter
- No symmetry - No definite shape
- Stars unevenly space out with no order
Spiral Galaxies
- Regular shaped intro a spiral pattern
- Large, Flat disk with curly arms (younger material found here!)
- Central bulge (nucleus and older material found here)
Barred-Spiral Galaxies
- Regularly shaped in a spiral pattern with a prominent bar through Nucleus
- Large flat disk with curly arms (younger material)
- Central Bulge (Nucleus = older material)
Elliptical Galaxies
- All bulge, No disk
- All stars, no gas
- typically redder (older stars)
Sun
Center of our solar system: located in the rotating galactic disk. located 26,000 LY from the Galactic Bulge.
Globular Cluster
Cluster of old stars found scattered throughout the galactic halo.
Nucleus (bulge)
Also known as central bulge.
- highest concentration of stars
- oldest stars found here
Galactic halo
- area of gas + dust
- has globular clusters scattered throughout
- held to galaxy by gravity
Galactic disk
- disk “curving arms” pattern
- younger material is found here
Parallax
Can only measure nearby stars, up to 100 LY away.
Radar
Solar System
Cepheid Variable
(same as magnitude for distance) (blinking stars)
Red Shift
Can only measure items up to 15 billion LY away.
