From the Atom to the (i forgot) Flashcards
The (major) steps of the Big Bang:
1. ?
1. Universe in a singularity, energy and mass same thing VERY hot (and it cools)
The (major) steps of the Big Bang:
2. ?
- Matter-Antimatter ‘war’, matter won (somehow)
Gravity leaves
The (major) steps of the Big Bang:
3. ?
- Strong nuclear leaves
The (major) steps of the Big Bang:
4. ?
- All four forces split
Sea of radiation (fundamental particles)
Too hot for nucleons to form
The (major) steps of the Big Bang:
5. ?
- Protons and neutrons form
Sea of radiation still
The (major) steps of the Big Bang:
6. ?
- Atoms (deuterium) can now form (nucleosynthesis)
Deuterium can also form helium
The (major) steps of the Big Bang:
7. ?
- Light is seen (photons trapped in matter)
Stars, planets and galaxies can now form
Evidence for the Big Bang?
- Cosmic background radiation
- Expanding universe
- 75% hydrogen, 25% helium
- Formation of stellar structures
Evidence for expanding universe by Hubble?
- Red shift of elements compared to lab results
2. Estimation of distance with luminosity
What do the two axes on a H-R diagram represent?
Luminosity
Temperature
What is the order of temperature in a H-R diagram?
OBAFGKM
hottest) Oh Be A Fine Girl Kiss Me (coolest
Where do 90% of all stars lie?
The Main Sequence
Stars with greater mass are brighter because?
To counter the great mass they have, they need more energy which makes them bigger and brighter
Above the Main Sequence, there are?
Giants and supergiants
Below the Main Sequence, there are?
Dwarves
The steps of star formation:
1. ?
Hydrogen gas clusters
The steps of star formation:
2. ?
Gas contracts into dark cloud
The steps of star formation:
3. ?
Gravity potential converted into heat (eventually nuclear reactions)
Protostar forms and the mass spins
The steps of star formation:
4. ?
Fusion starts
Debris gets knocked off
The steps of star formation:
5. ?
Main sequence star is formed
What is stellar equilibrium?
The balancing of the force of energy pushing out and the gravity pushing in for stability
What is a common feature between all main sequence stars?
They use hydrogen (proton-proton) fusion whereby 4 protons form helium and energy
What are the two types of fusion possible by main sequence stars?
- Proton-proton chain
- CNO cycle (for stars hotter than 1.8x10^7)
The steps of star death (for x < 8 SM):
1. ?
Small, duller, yellowish, warm sun (like ours)
- proton-proton fusion