HST image of the M16 nebula: pillars of creation

Physics 342
Principles of Astrophysics
Spring 2014

Tuesdays and Thursdays
3:20 to 4:40pm
ARC 105, Busch campus
Instructor: Eric Gawiser


Astrophysics is the application of physical principles to astronomical systems. In Physics 341 and 342 you will learn how to use gravity, electromagnetism, and atomic, nuclear, and gas physics to understand planets, stars, galaxies, dark matter, and the Universe as a whole. In Physics 342 we will focus on the question: How did we get here?

Our story will include the nucleosynthesis of hydrogen and helium in the first few minutes after the Big Bang 13.7 billion years ago, the formation of stars from this primordial gas, and the forging of heavier elements, such as carbon, nitrogen, and oxygen, among all others within these stars' nuclear furnaces. Around at least one star in the Universe some of these heavy elements coagulated to form a rocky planet with a tenuous atmosphere. On this planet Earth, 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 made inside dying stars. Literally, we are star dust. The goal of Physics 342 is to understand the physics of this remarkable story.

Some astrophysical systems are described by equations that are fairly easy to solve, and we will certainly study them. However, many interesting systems cannot be solved exactly. 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. As you will see, it will take us very far (through the whole Universe, in fact!) Another goal is to learn about recent advances in astrophysics, a very dynamic field of research.

Prerequisites for this class are two semesters of physics and two semesters of calculus. I will briefly review physical principles as we need them, but assume that you have seen them before. I will also assume familiarity with vector calculus. Some of the assignments may involve a bit of computation that can be done with programs like Excel, Google Spreadsheets, Maple, Matlab, or Mathematica. Note that Physics 341 is not a prerequisite for Physics 342; the two courses are designed to be complementary, but independent.

Lectures will follow an excellent set of lecture notes written by Prof. Chuck Keeton and modified by Prof. Saurabh Jha, and these lecture notes will be made available through our Sakai course website. For additional explanations, the recommended textbook for both Physics 341 and 342 is An Introduction to Modern Astrophysics (2nd edition) by Bradley W. Carroll and Dale A. Ostlie (affectionately known as the Big Orange Book). It provides a broad survey of astrophysics and covers the basics well. I will also draw from other sources as well, letting you know when I do.

Contact Information

Prof. Eric Gawiser
Room 303, Serin Physics Building (across Allison Road from the classroom), Busch campus
Email: gawiser[at]physics.rutgers.edu
Phone: 848-445-8874

Office hours: Mondays 2-3pm

Grading Policy

Grading will be based on biweekly problem sets (50%), an in-class conceptual midterm (5%), iClicker conceptual question scores (20%), and the final exam (25%).

There will be 6 problem sets during the semester, due every other Thursday at the beginning of class. Problem sets can also be turned in as PDF files via Sakai. It is your responsibility to meet the deadline! Late assignments will not be accepted.

You are encouraged to work in groups on the problem sets, but your write-up of the solutions must be your own. You must write down the names of your collaborators on your write-up. You must also cite any external sources you use (other than the class notes I post or the textbook). You may not use notes, assignments, or solutions from previous years of Physics 341 or 342.

The final exam will occur on Friday, May 9 at 12pm in SEC 118.

Schedule: Topics and Assignments

This syllabus may be modified as the semester progresses.

General concept
Jan 21,23
dimensional analysis; electron gas
10.2, 16.3, 16.6
Jan 28
The air we breathe
kinetic theory of gases
8.1, 10.2
Jan 30
planetary atmospheres;
hydrostatic equilibrium
10.1, 19.3
Feb 4
more planetary atmospheres
10.1, 19.3
Feb 6
Hot in here
blackbody radiation; planet temperatures
3.4, 3.5, 19.3
PS #1 due Feb 6
Feb 11,13
atmospheric heating; greenhouse effect
19.3, 20.2
Feb 18,20
Star light, star bright
stellar atmospheres; HR diagram
PS #2 due Feb 20
Feb 25
energy transport
Feb 27
nuclear fusion: energetics
5.4, 10.3
Mar 4
nuclear fusion: reaction rates
5.4, 10.3
Mar 6
nuclear reactions in stars
PS #3 due Mar 6
Mar 11
stellar structure; standard solar model
10.5, 10.6
Mar 13
in-class conceptual quiz; solar neutrinos
in-class quiz
Mar 18, 20
Mar 25
We are star dust
stellar evolution: low-mass stars
Mar 27
stellar evolution: high-mass stars
PS #4 due Mar 27
Apr 1,3
white dwarfs; neutron stars
Apr 8
Surveying the Universe
stellar pulsations
Apr 10
supernovae; cosmic acceleration;
dark energy
18.5, 29
PS #5 due Apr 10
Apr 15, 17
star and galaxy formation
12, 26.2
Apr 22
Apr 24
stars, disks, and planets
PS #6 due Apr 24
Apr 29
cosmic microwave background
May 1
Big Bang nucleosynthesis
May 9
Final Exam: SEC 118


Here are some web resources you may find illuminating or indispensable:

Other Items

Students with disabilities should consult the department policy.

Students will be held to the Rutgers policy on academic integrity.

Astrophysics at RutgersDepartment of Physics and AstronomyRutgers University

Last updated: January 9, 2014 by Eric Gawiser