Astrophysics deals with some of the most majestic themes known to science. Among these are the evolution of the universe from the Big Bang to the present day; the origin and evolution of planets, stars, galaxies, and the elements themselves; the unity of basic physical law; and the connection between the subatomic properties of nature and the observed macroscopic universe.

Three sequences of courses present the study of these topics in different scope and depth:

1. Physical Sciences 119-120-122/123/124/125 is a two- or three-quarter sequence that satisfies the general education requirements in the physical sciences. The first two quarters cover the formation and evolution of stars, the galaxy, and the extragalactic universe. Multiple options are offered for the third quarter. Natural Sciences 101-102-103-104-105 is a five-quarter sequence that satisfies the general education requirements in physical sciences and biological sciences. Natural Sciences 101 deals with the evolution of the universe.

2. For those seeking a more in-depth examination of selected astrophysical topics, the courses numbered in the 180s are offered, usually to be taken in the sophomore year or later. These courses are intended for students from throughout the College, and are especially suitable for students who may be planning to teach high school science or to work in a science museum or planetarium.

3. For students considering graduate work in astrophysics, the Department of Astronomy and Astrophysics recommends the program leading to a degree of Bachelor of Arts in Physics with Specialization in Astrophysics. The description of that program may be found in the Physics section of this catalog. Tutorial and research courses are available in addition to more informal opportunities for work and study in the Department of Astronomy and Astrophysics. Participation in a weekly seminar on current topics in astrophysical research is also recommended.

In the following course descriptions, L refers to courses with laboratory.

181. The Milky Way (=Astron 181, PhySci 181). PQ: Any 100-level general education sequence in chemistry, geophysical sciences, physical sciences, or physics. In this course we study what is known about our galaxy, the Milky Way. We discuss its size, shape, composition, location among its neighbors, motion, how it evolves, and where we are located within it, with an emphasis on how we know and what we know. Not offered 1999-2000; will be offered 2000-2001.

182. The Origin and Evolution of the Universe (=Astron 182, PhySci 182). PQ: Any 100-level general education sequence in chemistry, geophysical sciences, physical sciences, or physics. This course discusses how the laws of nature allow us to understand the origin, evolution, and large-scale structure of the universe. After a review of the history of cosmology, we see how discoveries in the twentieth century (the expansion of the universe and the cosmic background radiation) form the basis of the hot Big Bang model. Within the context of the Big Bang, we learn how our universe evolved from the primeval fireball. A. Olinto. Spring.

185. The Lives and Deaths of Stars (=Astron 185, PhySci 185). PQ: Any 100-level general education sequence in chemistry, geophysical sciences, physical sciences, or physics. In this course we study the observed properties of stars and the physics that enables us to understand them. Star formation, stellar evolution, and the deaths of stars is discussed. D. Lamb. Autumn.

187. Impacts and Catastrophes: Dynamics of Small Bodies in the Solar System (=Astron 187, PhySci 187). PQ: Any 100-level general education sequence in chemistry, geophysical sciences, physical sciences, or physics. This course explores aspects of the dynamics of asteroids and comets which are probably relevant to terrestrial cratering and mass extinctions. Such aspects include the fundamentals of celestial mechanics, order and chaos in the motions of bodies, and the mechanisms that transfer asteroids and comets from reservoirs of such bodies into the inner solar system. The question arises as to whether or not impacts of asteroids or comets on Earth pose a significant threat at the present time. P. Vandervoort. Winter.

200. Tutorial in Astronomy and Astrophysics. PQ: Any 100-level general education sequence in chemistry, geophysical sciences, physical sciences, or physics. Class limited to six students. May be taken either for a letter grade or for P/N or P/F. Students in this tutorial read topics in astronomy and astrophysics under the supervision of a faculty member. Students meet with the instructor in groups of one to three for approximately two hours per week to discuss readings on mutually agreed-upon topics. Staff. Summer, Autumn, Winter, Spring.

213. Origin and Evolution of the Solar System (=Astron 213, GeoSci 213). PQ: Consent of instructor. Knowledge of physical chemistry helpful. Representative topics include abundance and origin of the elements; formation, condensation, and age of the solar system; meteorites and the historical record of the solar system they preserve; comets and asteroids; planets and their satellites; temperatures and atmospheres of planets; and the origin of the earth's lithosphere, hydrosphere, atmosphere, and biosphere. L. Grossman. Winter. L.

241. The Physics of Stars and Stellar Systems. PQ: Phys 197 or consent of instructor. Building upon a student's previous knowledge of physics, this course introduces the astrophysics of stars and stellar systems with an emphasis on the physical nature of stars. Topics include the tools of astronomy, both observational and theoretical Hertzsprung-Russell diagrams, structure and evolution of stars, binary stars, star clusters, and end states of stars such as white dwarfs, neutron stars, and black holes. A. Königl. Autumn.

242. The Physics of Galaxies and the Universe. PQ: Astron 241 or consent of instructor. Physical laws are applied in attempts to understand the structures and evolution of galaxies, quasars, clusters of galaxies, and the universe at large. A. Olinto. Winter.

280. Current Topics in Astrophysics. PQ: Astron 241 and 242, or consent of instructor. An area of current research interest in astrophysics is explored in considerable detail. The topic varies, but some examples include the early universe, high energy astrophysics, magneto-hydrodynamics in astrophysics, observational cosmology, and cosmic microwave background. The current topic, physics of the early universe, focuses on recent developments in early-universe cosmology, and builds on the basics of the hot Big Bang model introduced in Astron 242. Topics include Big Bang nucleosynthesis, particle relics, anisotropies of the cosmic microwave background radiation, and inflationary cosmology. M. Turner. Spring.

299. Participation in Research. PQ: Third- or fourth-year standing and consent of instructor. Available for either Pass or letter grading. Students may register for this course for as many quarters as they wish; they need not work with the same faculty member each time. Students are assigned to work in the research group of a member of the faculty. Participation in research may take the form of independent work on a small project or assistance to an advanced graduate student or faculty member in his or her research. A written report must be submitted at the end of the quarter. Staff. Summer, Autumn, Winter, Spring. L.

301-302-303-304. Astrophysics I, II, III, IV. PQ: Consent of instructor and a minimum of one year of physics. (Normally students should have completed or be enrolled concurrently in Phys 321-322-323 or 341-342-343.) This course is designed to provide a firm foundation in the principles of astrophysics (e.g., hydrostatic equilibrium of a self-gravitating object, radiative transfer, and radiation from a diffuse gas) needed to carry out modern astrophysical research. Many astrophysical topics are discussed, but the emphasis is on elucidating general principles rather than attempting to survey the field. Weekly seminar on current topics in astrophysical research required. Staff. Autumn, Winter, Spring.

305. Radiative Processes in Astrophysics. PQ: Open to physics concentrators with advanced standing. Astron 242 and Phys 227, or consent of instructor. The course deals with the fundamentals of radiative transfer. The basic physics of radiation fields is studied and applied to astrophysical systems. Emission and scattering processes and the theory of radiative transfer are discussed in the context of model stellar atmospheres. Radiation processes important to astrophysics, such as Bremsstrahlung, cyclotron and synchrotron radiation, Compton scattering, and atomic and molecular transitions are covered, with an emphasis on their observational manifestations (e.g., spectra and polarization properties). S. Dodelson. Spring.

313. Extragalactic Studies. PQ: Consent of instructor. Topics include galaxies and intergalactic space, determination of Hubble's law, and peculiar extragalactic objects such as radio galaxies, Seyfert galaxies, and quasars. Not offered 1999-2000; will be offered 2000-2001.

315. Dynamics I (Fluids). PQ: Consent of instructor. This course examines the principles of hydrodynamics and hydromagnetics. Topics also include equilibrium and stability of fluid systems in astrophysics, waves, shocks, and turbulence. Not offered 1999-2000; will be offered 2000-2001.

316. Dynamics II (Particles). PQ: Consent of instructor. This course examines the dynamics of collisionless plasmas and stellar systems. Stochastic processes and kinetic equations, dynamics of galaxies and star clusters, and astrophysical plasmas are explored. Not offered 1999-2000; will be offered 2000-2001.

320. Relativistic Astrophysics. PQ: Consent of instructor. This course covers topics in special relativity, including the general theory of relativity and its experimental tests, and applications to astrophysical problems such as super-massive stars, black holes, relativistic star clusters, and gravitational radiation. Not offered 1999-2000; will be offered 2000-2001.

321. Cosmology. PQ: Consent of instructor. The standard Big Bang cosmological model, together with its tests and a discussion of nonstandard models, is covered. Topics include the Robertson-Walker metric, the 3K background, Big Bang nucleosynthesis, the determination of the age of the universe, and galaxy formation, as well as other current problems in cosmology. J. Frieman. Winter.

355. Radiation Measurement. PQ: Consent of instructor. Topics include methods of detection and measurements of radiation important in astronomy; theory of detectors in the X-ray, far-ultraviolet, optical, infrared, and radio regions of the spectrum; and the potential of various detectors for astronomical measurements. D. A. Harper. Autumn.

361. Interstellar Medium. PQ: Consent of instructor. Topics covered include the physics of interstellar gas, emission nebulae, HI regions, interstellar grains and molecules, and cosmic rays and the interstellar magnetic field. L. Hobbs. Spring.

383. Ptolemy's Astronomy and Other Sciences (=Astron 383, CSF 386, HiPSS 285). This is a course on Ptolemy's astronomy, astrology, and geography, which is the most highly developed state of each subject in antiquity. We discuss readings in class. N. Swerdlow. Winter.

PhySci 119-120-122/123/124/125. Introduction to Astrophysics. P. O. Vandervoort, D. York, R. Kron, J. Carlstrom, E. Kolb, P. Palmer. L: E. Kibblewhite. Autumn, Winter, Spring.

Phys 291-292-293. Bachelor's Thesis. PQ: Open to physics concentrators with fourth-year standing and consent of instructor. This yearlong sequence is designed to involve the student in current research. The student works on a research project in physics or a closely related field, such as astrophysics, leading to the writing of a bachelor's thesis. The project may be one suggested by the instructor, or one proposed by the student and approved by the instructor. Staff. Autumn, Winter, Spring

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