Astro 101 – 006 Spring 2011 (UNM@KAFB), T. Howard

Final Exam: Study outline

Stars -- basics

  • Distances -- parsecs
  • Visual, spectroscopic, and apparent binaries; proper motion
  • Luminosity is proportional to apparent brightness X (distance)2
  • Stellar magnitudes -- V and B color bands

Stellar classification

  • O B A F G K M -- understand this sequence, which end is hotter
  • H-R diagram: main sequence; red giant corner; white dwarf corner; its use as a tool; what does it plot?
  • What generality can we say about lifetimes of massive and lightweight stars? (main sequence lifetimes)

Star clusters and Interstellar medium (ISM)

  • Basic types of star clusters: open, globular
  • General description of ISM -- gas, some dust; low density; cold
  • Reflection vs emission nebulae
  • General process of star formation from ISM clouds
  • Older vs. younger clusters

Stellar evolution

  • Star’s position in H-R diagram depends on its evolutionary state
  • General evolution process of stars less than 8 solar masses
  • General evolution process of stars greater than 12 solar masses
  • Likely end state of very massive ( 25 solar masses or more) stars
  • Fusion powers the stars; core- and shell model; heavier element formation
  • Why is a black hole “black”?

The Milky Way galaxy

  • General description: bulge, disk, halo; where are the globular clusters? where is most of the gas and dust? How do stars move in disk vs. in the bulge?
  • What is there about our Galaxy (and other galaxies) that indicates “dark matter” is probably present? How much of our galaxy is probably Dark Matter?

Galaxies

  • Hubble’s “fork” classification scheme (3 types of galaxies)
  • Cepheids/RR Lyrae stars as distance indicators
  • Galaxies in Groups, Clusters, Superclusters
  • “Filament” like distribution of matter in the Universe
  • Rough idea of size scales: single galaxy to local group to cluster
  • Hubble’s Law: v = H0 X D
  • Galaxies interact and collide, merge

Cosmology & The Universe

  • The cosmological principle: homogeneous; isotropic; laws of physics the same everywhere
  • General ideas about Big Band and expansion of the Universe
  • Cosmic Microwave Background Radiation (CMBR)
  • Radiation dominated and matter-dominated eras; inflation
  • The Universe is likely “flat”, i.e., will expand forever
  • What do Supernovae type Ia tell us? about cosmic expansion; about Dark Energy? How much of the Universe is “visible” matter?

Life in the Universe

  • General thoughts about life, water, habitable zones
  • Extrasolar planets: found by radial velocity (Doppler) from the ground, or by transits
  • What are general characteristics of extrasolar planets found to date?
  • Possibilities for directly imaging extrasolar planets and confirming water
  • SETI -- why? Drake equation

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