Physics 342:
Principles of Astrophysics

Spring 2008

Astronomy at RutgersDepartment of Physics & AstronomyRutgers University
 

1. Course Description

Why are we here? That question lies beyond the realm of physics. But a related question is within our reach: How did we come to be here?

Briefly: Some 13.7 billion years ago, the universe borrowed energy from the vacuum to create hydrogen, deuterium, helium, lithium, and light. Some of the gas condensed into nuclear reactors called stars, which generated heavier elements (carbon, nitrogen, and oxygen, to name a few). Around at least one star, the heavy elements coagulated into a ball of rock surrounded by a tenuous atmosphere. On this planet, the energy from the star and the gas in the atmosphere were just right to allow the emergence of life. The energy that sustains us originated deep in the Sun, thanks to E=mc2. The atoms that comprise our bodies were forged inside dying stars. Literally, we are star dust.

The goal of Physics 342 is to understand the physics of this remarkable story. We will use gravity, electricity & magnetism, gas physics, and atomic and nuclear physics to analyze the structure and evolution of the astrophysical systems that enter the tale: planets, stars, galaxies, and the early universe.

Some of the astrophysical systems we will study are described by equations that are fairly easy to solve. Many others are not. Nevertheless, we can often use physical insight and approximate calculations to understand the salient features of a system without sweating the details. One goal of the course is to develop that skill. Another goal is learn about recent advances in astrophysics, a dynamic field of research!

Prerequisites for this class are two semesters of physics and two semesters of calculus. I will review physical principles as we need them, but will usually assume that you have seen them before. I will also assume familiarity with vector calculus. Note that Physics 341 is not a prerequisite for Physics 342; the two courses are designed to be complementary but independent.

The main textbook is An Introduction to Modern Astrophysics (2nd edition) by Bradley W. Carroll and Dale A. Ostlie. This book provides a broad survey of astrophysics; I will draw from different sections of the book to tell my tale. I will also use other sources for newer material, letting you know when I do.

2. Instructor and Venue

Prof. Chuck Keeton
Room 305, Serin Physics Building, Busch Campus
Email: keeton at physics.rutgers.edu
Phone: 732-445-5742

Office hours:

The class meets Tue/Thur 3:20-4:40, in ARC 105 on Busch campus.

3. Grading Policy

There will be six biweekly homework assignments, due in class on alternating Thursdays. If you must miss class, it is your resposibility to get your homework to me (or my Physics department mailbox) by 4:30 PM on the due date. Late homework may be turned in the next day by 3:00 PM for 80% credit. No homework will be accepted after 3:00 PM Friday.

You will have a chance to apply your knowledge to astrophysics news in the media or online. We will discuss details later in the semester.

The final exam will be a take-home exam, due at noon on Tuesday, May 6.

Your course grade will be computed as follows:

4. Topics, Schedule, and Supplemental Material

Here is a preliminary list of topics and tentative schedule for the semester. It may be revised as the semester proceeds.

General concept Date Topics
Introduction Jan 22, 24Dimensions and units, dimensional analysis; phases of an electron gas
The air we breatheJan 29Kinetic theory of gases
  Jan 31, Feb 5Planetary atmospheres
Why is it so warm?Feb 7Blackbody radiation; planet temperatures
  Feb 12, 14Atmospheric heating, greenhouse effect
Twinkle, twinkle, little starFeb 19, 21Stellar atmospheres; HR diagram
  Feb 26Energy transport
The energy we useFeb 28, Mar 4Nuclear fusion
  Mar 6Nuclear reactions in stars
  Mar 11Stellar structure; standard solar model
  Mar 13Solar neutrinos
  Mar 18, 20 NO CLASS: SPRING BREAK
We are star dustMar 25, 27Stellar evolution
  Apr 1, 3White dwarfs and neutron stars
Charting the UniverseApr 8Stellar pulsations
  Apr 10Supernovae, cosmic acceleration, and dark energy
How did we get here?Apr 15, 17Star and galaxy formation
  Apr 22, 24Stars, disks, and planets
Formation of the UniverseApr 29, May 1Cosmic Microwave Background

I have created a wiki for the course, which can be found at:

I will keep the schedule current there, and post homework assignments and solution sets. The wiki also provides supplemental material, including links to online astrophysics resources.

The reason I made the course website a wiki is to allow you to edit it. I encourage you to update the wiki with interesting material about astrophysics that you find. Working together, we can create a rich site with lots of interesting information about astrophysics!

5. Students with Disabilities

Click here for more information.

6. Rutgers Policy on Academic Integrity

The official Rutgers policy on academic integrity can be found at http://cat.rutgers.edu/in tegrity/policy.html.