Astronomy 100

Section 2, Fall 2008

Topics and Reading


Unit 1. August 25, 2008. Earth, Sun, and Sky

Reading

Topics

1. Shape and diameter of the Earth; how we know the Earth is approximately spherical.

2. Diameter of the Earth: how it can be measured.

3. Rotation of the Earth. Direction and period; rotation poles, equator, and latitude.

4. The sky, or celestial sphere; horizon, celestial poles, celestial equator, celestial meridian, declination; how they define directions; relation to latitude.

5. Motions in the sky: rising and setting, daily paths; where the stars rise and set.

6. Circumpolar stars.

7. Proof of rotation; the Foucault pendulum.

8. The orbit of the Earth and the path of the Sun; the ecliptic and the tilt of the Earth's axis (the obliquity of ecliptic).

9. The equinoxes and solstices.

10. Seasonal visibility of stars at night.

11. The seasons; origin and relation to ecliptic; solstices and equinoxes.

12. Tropics and the arctic.
br> 13. Ancient constellations (you are responsible only for the ones discussed in class).

14. Magnitudes of stars.

15. Modern constellations; what they are and generally when invented.

16. Star names: proper names, Greek letter names, Flamsteed numbers.

17.The Milky Way.


Unit 2. September 10, 2008. Moon, Planets, and Gravity Gravity

Reading

Topics

1. The lunar orbit; perigee and apogee

2. Phases of the Moon; rising and setting times at different phases

3. Rotation of the Moon -- far side and near side.

4. Earthlight on the Moon

5. Eclipses of the Moon and Sun; conditions.

6. Sidereal and synodic periods of planets

7. Apparent motions of planets; retrograde motion

8. Phases of Mercury and Venus

9. Ptolemy, Copernicus, and Tycho

10. Kepler and Kepler's laws

11. Galileo's observations

12. Velocity, acceleration, and force

13. Newton's law of gravity

14. The nature of an orbit; the orbit as a falling body

15. Weight and weightlessness

16. Kepler's generalized laws

17. The discoveries of Uranus, Neptune, and Pluto

18. Basic principles of spaceflight

Unit 3. September 22, 2008. Light and Telescopes

Reading

Topics

1. Protons, electrons, neutrons, and chemical elements.

2. The forces of nature.

3. Ions and isotopes.

4. The nature of light as an electromagnetic wave; wavelength and frequency

5. The electromagnetic spectrum

6. Photons and energy

7. Blackbody radiation and radiation laws; the Wien Law and the Stefan-Boltzmann law.

8. Spectrum lines

9. Telescopes and Observatories

Unit 4. October 1, 2008. Earth and Moon

Reading

Topics

1. The relation between the Earth and Moon; ages; tides and lunar rotation.

2. Surface features: Earth's ocean basins, continents, earthquakes, volcanos; the Moon's highlands, craters, and maria.

3. Internal structure of the Earth and Moon: core, mantle, crust.

4. Continental drift, convection in Earth's mantle; comparison to the Moon.

5. Earth's atmosphere and magnetic field

6. Formation of the Moon.


Unit 5. October 8, 2008. Other Planets and Moons

Reading

Topics

1. Size and masses in terms of Earth

2. Mercury's ancient surface and iron interior.

3. Clouds and atmosphere of Venus; Venus as a runaway greenhouse.

4. Volcanic Venus and its "young" surface.

5. Mars's similarity to Earth (seasons, rotation, polar caps).

6. Mars's varied surface with craters, volcanoes, and (once) water.

7. The controversy over the possibility of Martian life.

8. Interiors of the terrestrial planets

9. Similarities between Jupiter and Saturn 10. The outer planets' rapid rotations 11. The outer planets' clouds and storms.

12. The outer planets' internal heat.

13. The outer planets' interiors, compositions, and states of matter

14. The big satellites of Jupiter.

15. Saturn's rings and big satellite.

16. Similarities of Uranus and Neptune.

17. How Uranus and Neptune differ from Jupiter and Saturn. Smaller proportions of hydrogen and helium.

18. The satellites and rings of Uranus and Neptune (and Jupiter)

19. The oddness of Pluto and its similarity with Neptune's satellite Triton.


Unit 6. October 17, 2008. Creation and its Debris

Reading

Topics

1. Meteorites: stones and irons; chondrites as oldest bodies.

2. Asteroids: where they are; physical natures.

3. Relation of asteroids and meteorites; Earth-crossing asteroids and asteroid impacts.

4. Comets: structure; the two kinds of tail and comets' relations to the Sun.

5. Comet orbits; short period and long period; where the two kinds come from; Oort cloud and Kuiper belt.

6. Pluto and Kuiper Belt Objects

7. Meteor showers and storms.

8. Origin of the planetary system; assembly of planets from the dust of disk-shaped solar nebula; differentiation of planets (iron cores); origin of heavy bombardment; water on Earth from comet impacts; population of Oort cloud and debris left in the Kuiper belt; Pluto as part of the Kuiper belt.

Unit 7. October 23, 2008. Sun and Stars

Reading

Note: Don't try to read the assignments all at once. Keep pace with the lecture. We'll take up the Sun first, then go to stars.

Topics

1. Basic properties of the Sun: radius, mass, luminosity, surface temperature, rotation.

2. Photosphere: convection and granulation; spectrum and gross chemical composition

3. The solar corona and solar wind.

4. Sunspots as magnetic zones; sunspot cycle; active Sun phenomena and the relation between the active Sun and the Earth.

5. Solar interior; thermonuclear reactions.

6. Distances of stars. Parallaxes and how they relate to distance

7. Apparent and absolute magnitudes.

8. Motions of stars; radial velocities.

9. Spectra and the spectral sequence; the definitions of the various categories of stars.

10. The HR diagram: main sequence stars (dwarfs), giants, supergiants, subgiants, white dwarfs.

11. Luminosity classes

12. Carbon stars

13. Double stars and the mass-luminosity relation; the main sequence as mass sequence.

14. Brown dwarfs; L and T stars.

15. Star clusters.

16. Lifetimes of stars


Unit 8. November 8, 2008. Stellar Evolution

Reading

Again, do not read the material all at once; keep up with the lecture.

Topics

1. Gas in the interstellar medium: diffuse nebulae; interstellar clouds.

2. Interstellar dust; globules and molecular clouds

3. Star formation: gravitational contraction and the formation of disks.

4. Other planetary systems.

5. Lifetimes of stars on the main sequence

6. Hydrogen exhaustion and the creation of giant stars

7. Helium burning in giants, helium exhaustion, and the second ascent of the giant branch

8. Mass loss and the creation of planetary nebulae

9. White dwarfs and the Chandrasekhar limit

10. Evolution of high mass stars and the creation of supergiants

11. Nuclear burning to an iron core, supernovae, and the creation of the elements

12. Neutron stars, pulsars, and black holes

13. White dwarf supernovae


Unit 9. November 19, 2008. Galaxies and the Universe

Reading

Topics

1. Structure of the Galaxy: disk, halo and their differences; the likely nature of the nucleus.

2. Dimensions of Galaxy.

3. The mass of the luminous Galaxy and the existence of dark matter.

4. Age and evolution of the Galaxy; increase of metal content with time; the role of mergers.

5. Kinds of galaxies: spirals, ellipticals, irregulars.

6. Distances to other galaxies; Cepheid variables.

7. Masses of other galaxies and dark matter.

8. Clusters of galaxies.

9. Active galaxies; the likelihood of massive black holes at the centers of galaxies. 10. The velocity-distance (Hubble) relation; the meaning of the redshift, z, and the expansion of the Universe.

11. The Big Bang, the Hubble constant, and the age of the Universe.

12. The cosmic background radiation.

13. Expansion models. The curvature of the Universe.

14. The origin and evolution of the Universe; formation of galaxies.

15. Acceleration of the expansion and dark energy.