Download Astronomy 10B List of Concepts– by Chapter

Astronomy 10B List of Concepts– by Chapter
CHAPTER 8.SPECTRSOCOPY OF STARS
• What are the Definitions of brightness and luminosity (B = L/R2 )
• What is ‘Radial velocity’ and how is it measured?
• What is it Proper motion and how it’s measured?
• How do we Measure the rotation rate of stars?
• How do we Measure the magnetic fields of stars?
• How were spectral type letters originally assigned (strength of H lines)
• How are letters now assigned (types of spectral lines)
• Spectral types and temperature (which is hottest, coolest?)
• Spectral types and star color (which is bluest, reddest)
• Spectral types and ionization (molecules, atoms, etc)
• Two ways to measure surface temperature- which works better?
• Why don’t we see H lines in ‘O’ type stars?
• Note: Surface temperature is not core temperature
• What are Brown Dwarf Stars (types L & T)
CHAPTER 9. MEASUREMENTS OF STARS (AND H-R DIAGRAM)
• Mass distribution of stars (which are most common?)
• Mass- temperature relationship
• Mass- luminosity relationship
• Measuring the mass of stars (we need two things)
• Range of stellar masses (Minimum and rough maximum)
• Mass-luminosity equation (approximate)
• Measuring the diameters of stars (two ways)
• Binary stars, and spectroscopic binaries
• What is H-R Diagram, what are the axes, and why abbreviate it?
• Which equation accompanies the H-R diagram? L=R2T4 (not in book)
• Where on the H-R diagram do we find:
o The Main Sequence
o White Dwarves,
o Red Giants,
o Brown Dwarf
o High-mass Main Sequence Stars and
o Low-Mass M.S. Stars
CHAPTER 10: CELESTIAL DISTANCES
• What was the ‘first step’ of the measurement ladder? (Walking)
• How did Eratosthenes find the size of the Earth?
• How is the Metric System related to size of Earth?
• Using triangulation to measure distances
o How: baseline and two angles
o Definition of parallax
o First measurement of the Sun-Earth distance (AU) (Venus transit)
o Definition of a Parsec
o Why is the parallax of stars so hard to measure?
o Maximum distance possible with this method
• ‘Standard Candles’ (book says ‘Standard Bulbs’ but they’re really
candles)
o Cepheid variable and the period-luminosity relationship
o Spectroscopic parallax – the H-R diagram & distance to clusters
o Supernovae Ia
o Largest distances in space.
CHAPTER 11: THE INTERSTELLAR MEDIUM
• What is the Definition of the “interstellar medium”?
• HI regions, how we detect them, temperature, density, etc
• HII regions and how we detect them, temperature, density, etc
• Ultra Hot Gas and how we detect it, temperature, density, etc
• Molecular Clouds – detecting them, temperature, density, etc
o Molecules and Dust are inter-related
o Interstellar extinction and reddening
o Why does dust block visible light better than radio waves?
o Why dust cools molecular clouds better than other ISM
o Why are these where stars form?
CHAPTER 12: STAR FORMATION
• Observations of star formation
• Stars form in molecular clouds because …
• Stars form in clusters because …
• The stages of star formation
• Why does a disk form?
• Why do jets form?
• Differences between a proto-star and a main sequence star
• Definition of Zero-Age Main Sequence star
• Stellar mass and the rate of star formation (and evolution)
• The H-R diagram and star formation
• Finding the age of star clusters and the H-R diagram
• Planetary formation
CHAPTER 13: STELLAR EVOLUTION
• The main sequence (M.S.)
o What are these stars doing?
o How long will they be doing this (what fraction of their lives)?
o Relation between stellar mass and main sequence lifetime
• Red Giants – and the red giant branch
o What are the stars doing?
o How big do they get? Why?
o How long will they be there?
• Evolutionary stages of a low-mass star
• Evolutionary stages of a high-mass star
• Changes in a star’s core when it runs low on Hydrogen
• Hydrogen shell around the core
• Helium fusion (difference between He flash and He conflagration)
• What’s the heaviest element whose production gives off energy?
• What happens when a Star’s core is made out of that element?
• H-R diagram and the age of a cluster of stars
CHAPTER 14 WHITE DWARF & NEUTRON STARS
• White Dwarf Stars
o Upper limit for the mass of a White Dwarf (size, density, etc)
o Electron degeneracy
o Stellar mass-loss on way to becoming a White Dwarf
• Supernovas (ae)
o Implosion/Explosion
 Iron core & end of fusion - What’s special about Iron
o Energy given off, fraction as light, neutrinos, other
o Nucleosynthesis: how elements heavier than Iron are made
• Neutron Stars
o Neutron degeneracy
o Upper limit for the mass of a Neutron Star (size, density, etc)
o Formation
• Pulsars
o Lighthouse model
o Why can’t we see all Pulsars (even if they are close by)?
o Who discovered Pulsars but was betrayed by her advisor?
o How big of jerk was he?
• Recurring Novas & Supernovas Type I
o Binary star systems
o Novae
o Supernovae?
Astro 10B Outline & Study Guide
CHAPTER 15 BLACK HOLES & GENERAL RELATIVITY (G.R.)
• Classical relativity
o Inertial Frames of Reference
o Some measurements have different numbers but Physics is same’
• Special relativity (observations & tests)
o Speed of light is the same in all FOR’s
o Space and time are affected by matter’s motion
o Space + Time = spacetime
• General relativity
o The equivalence principle
o Gravity is not a force – it is a warping of spacetime
o What travels in straight lines in spacetime?
o Tests
 Clocks in the ground and top floor of a building
 Precession of Mercury’s orbit
 Apparent shift of star’s positions during solar eclipse
• Black Holes
o Black Holes – classical view (escape velocity)
o Black Holes – G. R view (curved spacetime so light cannot
escape)
o The event horizon, Schwarzschild radius and mass
dependence
o Detecting black holes
o Light from around Black Hole red-shifted
o Not cosmic vacuum cleaner
CHAPTER 16 THE MILKY WAY GALAXY
• Three main parts of the Milky Way: Disk, Halo, Nuclear Bulge
• Dimensions, mass and color of the parts
• Which part of the Milky Way has:
o Spiral arms
o Young & metal rich stars –
o Old & metal poor stars
o Gas & Dust
• Sun location and orbit within the Milky Way
• Determining the mass of the Milky Way (two ways)
• Dark matter – observations, distribution and explanation
• Where is the 3,000,000 M Black Hole?
CHAPTER 17 TYPES OF GALAXIES
• Types of galaxies – spiral, elliptical, irregular
o masses, luminosities, mass-light ratio, color, gas & dust and dia
• Which type of galaxy is the Milky Way?
• Distances to galaxies
• The Hubble Law
o The Hubble age of the Universe
o Is spacetime expanding or is the matter just flying apart?
CHAPTER 18 AGN’S, QUASARS
• If a QSO is a AGN, what are TLA's?
• Quasars are called “quasi Stellar objects” (QSO)
• Luminosity, diameter, energy source, distance - age
• Seyfert galaxies & Active radio galaxies
• Jets
CHAPTER 19 GALAXIES, CLUSTERS AND LARGE SCALE STRUCTURE
• Definitions (Cosmological principle, isotropic)
• Giant elliptical galaxies and clusters
• Distributions of galaxies, groups and clusters in space
• Galactic evolution & collisions
• How has star formation changed compared with 8 Byrs ago?
CHAPTER 20. THE BIG BANG AND EARLY UNIVERSE
• Einstein's cosmological constant
o May be equivalent to what discovery?
• Big Bang tries to explain …
• What observation could the original Big Bang theory not explain?
• Stages of the Big Bang
o Time & temperature
o Formation of matter
o Universe become transparent
• Cosmic Background radiation (CBR)?
o Who discovered
o Observed in which band?
o When we look at the CBR, we see remains from
o The CBR spectrum corresponds to which temperature?
o The small variations in the CBR match what distribution?
• GUT’s
o Forces unify at temperatures
o Which forces were unified a hundred years ago ?
o Inflationary universe &GUTs explain observations
o universe inflate faster than the speed of light
o matter-anti-matter imbalance
o the density of the universe
o What is the last enduring problem with GUTs?
• About what fraction of the universe is dark energy?
• What is Dark Energy?
• About what fraction of the universe is dark matter?
• What is Dark Matter?
• About what fraction of the universe is normal matter?
• What is Normal Matter?