Physical Sciences 110; 12 - 1:45 PM TuTh

This is a one-quarter course on stars, stellar evolution, and topics known collectively as "high energy astrophysics" as it applies to stellar phenomena. Thus the subject matter includes, in addition to the study of the stars themselves - their observed properties and their formation and evolution - such topics as novae, supernovae, nucleosynthesis (the origin of the elements), x-ray sources, pulsars, gamma-ray bursts, neutron stars, and black holes. As a lead up to these topics, we shall discuss aspects of basic astrometry (the positions of the stars), distance determination, Newtonian physics, flux and energy, simple Keplerian orbit theory, quantum mechanics, stellar spectroscopy, equations of state (pressure as a function of density and temperature), and nuclear physics.

Cosmology and extra-galactic astronomy will also be touched on in several lectures, though not in nearly as great a depth as in Ay 13, which was offered last quarter. Other courses being offered by the Astronomy Department this year are posted at

Note that Ay 112 is being taught this same quarter by Jonthon Fortney for those of you interested in a more rigorous upper division course on a similar topic. Doug Lin is also reach Ay 18 on planets this quarter - similar difficulty, different topic. Ay 12 is especially intended for science majors and counts toward satisfying requirements for the astrophysics minor. It is heavily physics oriented. However, it should also be accessible to highly motivated non-science majors with some background in math and exposure to physical principles (see below). Our studies in Astronomy 12 will require knowledge of simple mechanics and some basic ideas about radiation theory, quantum mechanics, and nuclear physics which we shall develop as we go along, using astrophysical applications as examples. The second half of the quarter deals with the evolution of stars, beginning with their formation on the "main sequence", continuing their lives as bright celestial objects, and ending as the star collapses to a white dwarf, neutron star, or black hole. Various phenomena associated with star death (such as supernovae and nucleosynthesis) will be discussed as will energetic phenomena associated with collapsed stars and binary stars.

While this course will be taught at a higher level (more math and physics) than Astronomy 2 and 3, the material is mostly self-contained. No previous college level math, physics, or astronomy is required, though it certainly will help. It will be assumed however that the student has mastered algebra at the pre-calculus level, including logarithms, simple trigonometry, and fractional powers, and has some familiarity with basic scientific concepts and reasoning. Elementary calculus will sometimes be used in classroom derivations because, for those understanding calculus, it is the easiest and clearest way of obtaining results. It is not expected, however, that the student will need to use calculus on homework assignments or tests. There will be considerable emphasis on the physical processes believed to be operating in stars and the development of basic physical concepts will form a core part of the course. Prior physics classes (e.g., 5AB or 6AB) will definitely make the course easier.

Performance in this course will be judged on the basis of i) an in class, graded mid-term exam (roughly 25%); ii) a similar final exam (roughly 30%); iii) 4 graded homework sets (roughly 35%); and in class participation (up to 10%). Questions and class-room discussion are encouraged, both for your benefit and to aid me in properly pacing the course. This course counts towards the astrophysics minor.

The recommended text (but not required) for this course is Voyages to the Stars and Galaxies: Third Edition by Fraknoi, Morrison, and Wolff (FMW). It is reasonably modern, but qtoo superficial mathematically for my liking. It does give many interesting links on the web for further study though. Another book that I would recommend especially for the second half of the course is An Introduction to the Sun and Stars by Simon Green and Mark Jones (Barnes and Noble, 2004). This is better than the Fraknoi book at what it covers, but lacks most of the material treated in the first few weeks of the course. Both books are on reserve at the Science Library.

Specific readings in our recommended text Fraknoi, Morrison, and Wolff, and in Green and Jones will be suggested below.

Large amounts of useful information are increasingly available on the internet. We will maintain a website for the course at

An interesting website is the free ``hypertext'' astronomy textbook by Nick Strobel at

Click on - ``Jump to Chapters listing''.

Many other useful free textbooks can be downloaded or looked at for their treatment of specific topics at

You are not assigned to read any of these, but there is probably one there that discusses the subject at the level you want. I find the ones by Marcia Rieke, James Schombert, and the one simply labeled ``Stars, Galaxies, and Cosmology'' (near the end) to be close to our class level. The ones by Pierce, Collins, Tatum, Bertschinger are more like Ay112 (and beyond). There are also some interesting texts on cosmology.

Your principal source of information however, will be class and the slides presented there (and archived on the class website). Your attendance is strongly encouraged. Taking accurate detailed notes is also strongly advised, as you will need them in order to do the homework and to study for the two exams.

Class will meet twice weekly (TuTh 12 AM) in the Physical Sciences Building, Room 110. There will be a Graduate Teaching Assistant, Tiffany Hsyu. Her office is in Interdisciplinary Sciences, room 255 and her phone number is 9-5722. Students can stop by her office by making an appointment, but she will definitely be present for official Office Hours which are still being determined but presently 12:00 - 2:00 PM Mondays in the Interdisciplinary Sciences Building, Room 126. There will also be a weekly Discussion Section that Tiffany will run. This section is ``optional'' in the sense that if you are doing well in the course and don't need help with the homework, you don't have to attend, but if you do poorly in the class and have not attended Section, it will be held against you, i.e., you will not get the ``extra credit'' that comes from participating in Section. The time and location for the Section is still being determined. I will also be available during office hours (2:00 - 3:30 PM Tu, IDS 259) or at other times by appointment, though Tiffany should be the one you first turn to with questions regarding course material. It will be advisable to purchase a small inexpensive calculator, if you do not already own one. Be sure to get one that does powers, roots, trig, and logarithms.

A general outline of topics and relevant page numbers in the text follows. The actual material covered will vary somewhat and the topics near the end will depend on our rate of progress. Roman numerals do not correspond to the lecture number, but do indicate the approximate sequencing of topics. The references are based on the 3rd edition of Voyage to the Stars and Galaxies (FMW), Green and Jones An Introduction to the Sun and Stars (GJ), and Nick Strobel's hypertextbook (NS). You may also want to begin by looking at NS ``Appendix B: Quick Mathematics Review''.



The scope of the Universe and the place of the stars in the grand scheme of things. Overview of course material. FMW Prologue; Chapter 1, 9.1; NS ``Astronomy as a Science and a Sense of Scale''.


The location of the sun in the sky. Right ascension, declination, longitude, and latitude. The celestial sphere and coordinates.

FMW 1, 3; NS ``Astronomy Without a Telescope''


1. Newtonian physics, fundamental forces, gravitation.
2. Kepler's Laws
3. Energy: kinetic, gravitational, electrical, thermal, nuclear.
4. Weighing the galaxy. Evidence for dark matter.

FMW 2, 16; NS ``Newton's Law of Gravity''


1. Luminosity, flux, magnitude definitions
2. Parallax's and proper motions; distance determinations
3. Cepheid variables; P-L relations; distances to local groups
4. Other standard candles - brightest stars, H II regions, supernovae
5. The Tully-Fisher relation.
6. Hubble's law

FMW 10; NS ``Stellar Properties'' (first half) and last part of ``Other Galaxies and Active Galaxies'' - Steps to the Hubble Constant; GJ 3


1. General properties
2. Transparency of Earth's atmosphere
3. Black body radiation and the greenhouse effect
4. Stellar temperatures
5. Quantum physics - the Bohr atom
6. Emission and absorption of radiation
7. Doppler shift
8. Stellar spectra

FMW 4, 5; NS ``Electromagnetic Radiation''; GJ 1, 3


1. Determination of stellar radii, surface temperatures, mass, composition, etc. 2. Hertzsprung-Russell diagram 3. Star clusters; distances, ages 4. Stellar populations; history of the Galaxy.

FMW 8, 9; NS ``Stellar Properties'' (second half); GJ 3, 4


1. The viral theorem
2. The Jean's mass
3. The interstellar medium and molecular clouds
4. Observational evidence for star formation

FMW 11, 12; NS ``The Interstellar Medium'' and the first part of ``Lives and Deaths of Stars''; GJ 4, 5


1. Concepts of pressure and equation of state
2. Kinds of pressure
3. Hydrostatic equilibrium
4. The sun, a typical star
5. Degeneracy pressure and the minimum mass of a star
6. Nuclear physics
7. Hydrogen burning and the main sequence of the HR diagram
8. The solar neutrino ``problem''

FMW 6, 7; NS ``Our Sun and Stellar Structure''; GJ 1, 2, 6


1. Helium burning in stars
2. Red giant stars
3. The s-process: making tin and lead from iron
4. Planetary nebulae
5. Formation and properties of white dwarf stars

FMW 13; NS ``Lives and Deaths of Stars'' (middle part); GJ 7, 8, 9


1. Advanced stages of nuclear burning. The role of neutrinos
2. Observed properties of supernovae
3. The gravity bomb: How supernovae of Types II and Ib work
4. Supernova 1987A
5. Nucleosynthesis of elements up to nickel
6. The r-process: Making gold and platinum from iron.
5. Supernova remnants

FMW 14; NS ``Lives and Deaths of Stars'' (last part); GJ 7, 8


1. Mass exchange in binary star evolution
2. Novae
3. Type 1a supernovae

FMW 14; GJ 9


1. Properties of neutron stars and black holes
2. Accreting x-ray sources
3. Pulsars

FMW 14, 15; GJ 9


FMW 15, 18-interlude