AST 4001: Astrophysics I
Stars and Stellar Evolution

Last Update on Wednesday, 03-Sep-2008 22:39:49 AEST


Prof. Dr. Alexander Heger, 342F Tate, (612)-625-9283

Class dates, time, and location

MTWTh, 10:10-11:00 AM

Physics 236A

Office Hours

Wednesdays, 13:00-14:30

Credits and Requirements

4.0 cr

AST-2001, Phys 2601; A-F or Aud


AST 4001 - Astrophysics I - is a survey course on the astrophysics of stars, stellar evolution, and stellar populations. The students will learn about the formation, evolution, and deaths of stars, their interiors and observable atmospheres, their formation environments, remnants, and classifications. They will learn about the origin of the elements and their synthesis in stars, chemical evolution, stellar populations in the Milky Way, and the galactic distribution of stars. Both observational and theoretical perspectives will be included.

Among the topics the students will learn in this class are:

The learning goal of this class is that the students will obtain an overview of the astrophysics related to stars - what are the phenomea and relations observed and how they can be explained.

There will be bi-weekly problem sets (not including class project), 2 mid-semester exams, and a final exam.

The students will use a stellar evolution code to perform numerical simulations of stars and stellar evolution (see below). Specific problems will be assigned. Basic knowledge of FORTRAN/FORTRAN90 is required to modify and compile the code. At the end of the class students should be able to perform this kind of scientific work.


"An introduction to the Theory of
Stellar Structure and Evolution"
by Diana Prialnik


Relevant material is the class lectures.

In class


Problems sets roughly every two weeks, Tuesdays, due before class

Please check homework assignments for questions or clarifications timely, not just before the due date so you have a chance to see me during office hours or ask after class.


Class Project

Build your own Star

Supplementing the class material the students will use a modern stellar evolution code to perform their own simulations of the life of a star. The students will make "numerical experiments" on how the evolution of stars changes when initial conditions or "input physics" is changed - e.g., how differences in nuclear reaction rates used change the evolution of stars. Such differences could, e.g., test the limits of current experimental and theoretical uncertainties in these nuclear reaction rates.

The class will use Bill Paxton's EZ Stellar Evolution code
Uses Linux gfortran (WIKI at

Another free FORTRAN compiler is g95 and can be downloaded for most platforms from


Assignments will usually be due at homework assignment dates. While you are invited to help each other with getting the code to work and how to modify it for the tasks at hand, I do expect that every student can and does run the project assigments by himself/herself, and does do and submit his/her own independent analysis.

Class Calendar

Additional Literature


Accommodations for Students With Disabilities: Participants with special needs are strongly encouraged to talk to the instructors as soon as possible to gain maximum access to course information. All discussions will remain confidential.

University policy is to provide, on a flexible and individualized basis, reasonable accommodations to students who have documented disability conditions (e.g., physical, learning, psychiatric, vision, hearing, or systemic) that may affect their ability to participate in course activities or to meet course requirements. Students with disabilities are encouraged to contact Disability Services and their instructors to discuss their individual needs for accommodations. Disability Services is located in Suite180 McNamara Alumni Center, 200 Oak Street. Staff can be reached at or by calling 612/626-1333 (voice or TTY).

Diversity and Collegiality:

This course draws graduate students from a variety of disciplines. This diversity of academic experience, assumptions regarding learning, and ways of approaching problems is one of the most enriching aspects of the course. In addition, every class is influenced by the fact that students come from widely diverse ethnic and cultural backgrounds and hold different values. Because a key to optimal learning and successful teaching is to hear, analyze, and draw from a diversity of views, the instructors expect collegial and respectful dialogue across disciplinary, cultural, and personal boundaries.

Student Mental Health:

As a student you may experience a range of issues that can cause barriers to learning, such as strained relationships, increased anxiety, alcohol/drug problems, feeling down, difficulty concentrating and/or lack of motivation. These mental health concerns or stressful events may lead to diminished academic performance or reduce a student's ability to participate in daily activities. University of Minnesota services are available to assist you with addressing these and other concerns you may be experiencing. You can learn more about the broad range of confidential mental health services available on campus via

Student Conduct:

Instructors are responsible for maintaining order and a positive learning environment in the classroom. Students whose behavior is disruptive either to the instructor or to other students will be asked to leave. Students whose behavior suggests the need for counseling or other assistance may be referred to their college office or University Counseling and Consulting Services. Students whose behavior may violate the University Student Conduct Code may be referred to the Office of Student Judicial Affairs.

Sexual Harassment:

University policy prohibits sexual harassment as defined in the University Policy Statement ( adopted on December 11, 1998. Complaints about sexual harassment should be reported to the University Office of Equal Opportunity, 419 Morrill.

Academic Dishonesty:

Students are expected to do their own assigned work. If it is determined that a student has engaged in any form of Academic Dishonesty, he or she may be given an "F" or an "N" for the course, and may face additional sanctions from the University. Academic dishonesty in any portion of the academic work for a course shall be grounds for awarding a grade of F or N for the entire course. See

Attendance and Participation:

Instructors expect students to arrive on time and attend the full class period.