Syllabus

Scope and Spirit of the Course

ASTRO-414 is a lecture course on the theory of stellar structure and evolution for advanced astronomy undergraduates. In this course students will learn the following:

• The basic physical principles required in constructing stellar models.

• The basic equations of stellar structure, and simple stellar models for main-sequence stars.

• The results of more sophisticated (numerical) stellar models and how they explain main sequence stars.

• The evolutionary stages of stars after the main sequence phase through the formation of compact objects and highlight the underlying physical considerations.

The topics will be covered at a fairly advanced level and substantial astronomy background will be needed. The course emphasizes analytic calculations of the processes at work in stellar interiors. Homework assignments are an integral part of the course and an important means by which the students will learn the principles of stellar structure and how to apply them.

The most important rules and information about this course are given below. See also the other tabs in this web site for a wish list of topics to be covered, expectations and advice on homeworks, and various general policies.

Textbooks

The material is drawn primarily but not exclusively from the textbooks below; there is no required textbook for this course. But keep in mind that the course content is defined by what is presented in class, not by the textbooks. Some of these textbooks are available on line (through the Penn STate libraries) and others have been placed on reserve in the Physical and Mathematical Sciences Library (PAMS library, 201 Davey Lab).

Here is a list of textbooks most relevant to and at the level of this course. The boldface code in square brackets is the abbreviation for this book used throughout this syllabus and list of topics.

• [Prialnik] An introduction to the Theory of Stellar Structure and Evolution 2nd ed., by D. Prialnik (2010, Cambridge University Press); Call Number: QB808.P75 2010. A physical copy of this book is on reserve in the PAMS Library.

• [BV] Introduction to Stellar Astrophysics, Volume 3: Stellar Structure and Evolution, by E. Böhm-Vitense (1989 or 1992, Cambridge University Press); Call Number: QB801.B64 1989 v.3 1989 (or 1992) v.3. The 1992 edition of this book is available electronically through the PSU library (authentication with PSU credentials is needed).

• [Guidry] Stars and Stellar Processes, by M. Guidry (2019, Cambridge University Press); Call Number: QB808.G85 2018. A physical copy of this book is on reserve in the PAMS Library.

• [LL] Understanding Stellar Evolution, by H. Lamers and E. Levesque (2017, IOP Publishing); Call number: QB806.L35 2017. This book provides very useful, concise summaries of the topics covered in this course. It is available electronically through the PSU library (authentication with PSU credentials is needed).

Other useful but more specialized or advanced textbooks:

• [HK] Stellar Interiors: Physical Principles, Structure, and Evolution, by C. J. Hansen and S. D. Kawaler (1994, Springer-Verlag); Call Number: QB808.H36 1994 (or 2004). The 1992 and 2004 editions of this book is available electronically at one of these links: 1994 Edition or 2004 Edition (authentication with PSU credentials is needed).

• [KW] Stellar Structure and Evolution, by R. Kippenhahn and A. Weigert (1990, Springer-Verlag); Call Number: QB808.K57 1990 (or 1990b). A newer and updated edition by  R. Kippenhahn, A. Weigert and A. Weiss 2012 (or 2013) is also available. This is a very advanced and “authoritative” book that includes, among other things, a discussion of the numerical methods used to compute stellar models. It is available electronically through the PSU library (authentication with PSU credentials is needed).

• [Clayton] Principles of Stellar Evolution and Nucleosynthesis, by D. Clayton (1968, McGraw-Hill); Call Number: QB464.C55. This is a specialized and very advanced textbook that focuses on the nuclear reactions that power stars.

• [Phillips] The Physics of Stars, by A. C. Phillips (2008, Wiley); Call number for 1999 Edition QB801.P48 1999. This is a specialized textbook that focuses on the physical processes in stellar interiors. 

The list of topics to be covered are listed in the Topics tab of this syllabus. This list should be regarded as a wish list because some topics will be covered in more depth than others and topics near the end of this list will only be covered to the extent that time permits.

Expected Background

Since ASTRO-292 and PHYS-237 are pre-requisite courses students should be very familiar with the following topics (a) observations and measurements of fundamental stellar properties, (b) the Hertzprung- Russel diagram and its use in classifying stars, (c) the elementary theory of stellar structure and evolution as covered in ASTRO-292, (d) elementary quantum mechanics, specifically quantum mechanical tunneling, (e) elementary statistical mechanics of Fermions and Bosons, (f) the properties of the Planck function and blackbody radiation, (g) basic particle kinematics and mechanics in special relativity. Stu- dents should also be able to solve simple differential equations and be familiar with the solutions of the well-known differential equations of mathematical physics (e.g., the wave equation and the Schröedinger equation). Although some of the principles above will be reviewed before they are applied, those reviews will be very brief and their purpose is to remind students of concepts that they should already know, not teach them these concepts anew.

In addition to the above, students are expected to have some rudimentary computing skills. Specifically, one should be able to use a programming language that is common for astronomical applications (e.g., Python) to read tables of data, carry out simple manipulations of the data, and make simple (but clear and effective) plots of the results. Common spreadsheet programs (such as Excel) can be used to carry out some of the data manipulations needed for this course but the plots that these programs produce are not acceptable. The above skills will be needed in some homework assignments that ask one to analyze the structure of stars based on tables of their internal properties. 

This Web Site and Canvas Page

On this web site you will find the basic course information and a calendar of important events (Home tab), the detailed syllabus (this tab), a wish list of topics to be covered in this course (Topics tab) instructions and advice on homeworks (Homework tab). Canvas will be used for keeping a running record of the topic covered in class, distributing documents and other materials, and assigning and submitting homeworks. The Canvas site for this course already includes a PDF copy of the course packets and the homework packet. 

Materials Available Electronically Through Canvas

• Problem Packet. – Exercises that will be assigned during the semester, available in PDF format (there is a link to the packet on the main Canvas page and the link will also be given in each homework assignment). You will be asked to turn in some of the exercises for credit and others will be used for your own practice. The initial version of the problem packet includes the problems that are ready at at the beginning of the semester. This set may be supplemented by other problems added to the problem packet later.

• Solutions Packet. – Solutions to the exercises in the problem packet. These will be posted on Canvas after the due dates of assignments. They are all bundled together in one PDF file and that file will be updated after each assignment (there is a link to the packet on the main Canvas page and the link will also be given in each homework assignment. 

Printed Materials Distributed in Class

The following printed packets are distributed in print at the beginning of the semester. Electronic copies in PDF format can be found on the Canvas web site for the course. There may be additions to these materials over the course of the semester. 

• Notes Packet.– Several detailed tutorials and note sets to supplement topics covered in class (e.g., detailed notes and derivations), nuclear reaction data, fundamental constants, etc

• Illustrations Packet. – Figures and tables used in class to supplement the lecture material. These figures encode a great deal of essential information. It is important to learn how to read these figures and extract the relevant information from them.

On several occasions during the course there will be review sessions to recap what was covered in the lectures. The slides from these sessions will make up the Review Packet and they will be distributed in class in print at the begining of each session.  Electronic copies in PDF format can be found on the Canvas web site for the course. 

You should bring the Notes Packet, Illustrations Packet, and Review Packet with you to the tests. You will actually need these materials during the tests. You can annotate the printouts to add extra information that may be useful to you (see details below in the Assessed Work section).

Assessed Work and Basis for Grades

The assessed work for this course consists of regularly assigned homework and three tests (there is no final exam). The final grade is based on a weighted combination of scores from the above (25% for each test, 25% for all homeworks combined). The final, letter grades will be assigned after considering the complete record of performance of each student and they will follow these rules:

A final, average score of... is guaranteed a grade of...

50% or higher D or better

60% or higher C or better

90% or higher A– or better

The dates of the tests are:

Test 1: Thursday, February 8, 2024

Test 2: Tuesday, March 19, 2024 (10 days after spring break) 

Test 3: Thursday, April 18, 2024 (penultimate week of classes)

If the university is closed because bad weather (or any other reason) on the day of a scheduled test, the test will be given during the immediately following class period, unless other instructions are issued.

The tests will be given in the regular classroom (unless announced otherwise) during regular class time. Each test will examine the material covered in class since the previous test as well as essential background and relevant material from earlier in the course.

The printed course packets (notes, illustrations, reviews; see above) are allowed in the tests and will actually be needed. Additional notes that you take during class in your note books, books or copies of pages from books, homework problems or earlier tests, and their solutions, and copies of slides that are not part of the review packet are not allowed (most of the slides shown in class just include figures from the illustrations packet).  You are allowed to add your own annotations and explanations on the printed materials that you bring with you. But note the following:

• You should maintain a single set of printed materials for all tests and add your notes to that set only.

• You cannot add any attachments, such as Post-It notes; all you can do it write by hand on the existing pages. 

• You cannot print a fresh set of these materials for each test and annotate them anew. 

Calculators are allowed, but other electronic devices, such as phones, tablets, or laptops are not allowed (even if the intent is to use them only as calculators).

As a rule, no makeup tests will be given. Exceptions may be granted if a student missed the regularly scheduled test because of a serious medical or family emergency or because of university business. It will be up to the instructor to approve the request for a makeup test. Students requesting a makeup test are expected to be cooperative and forthcoming with information and evidence to support their request (for example, a letter from the university or from a doctor). If a makeup test is approved, its content will very likely be different from that of the regular test. The date and time of the makeup test will be set by the instructor after consultation with the student(s). Make-up tests will be given after the regular test, not before, and must be completed before the time of the next regularly scheduled test or the end of the semester in the case of the last test.

Homeworks will be assigned every week or every other week and their due date and time will be announced when they are assigned. Typically, the due date will be one week after the assignment is issued. By the deadline, students are expected to upload their homework answers on Canvas. Students should submit their answers to each homework through Canvas as a single, self-contained PDF file. They can be written by hand and then scanned or photographed (e.g., using Microsoft Lens or Adobe Scan), or they can be written on a tablet and exported to PDF, or they can be typed (or they can be produced by some other method that creates a PDF file). A PDF resolution of 200–300 dpi (dots per inch) is prefered because it results in readable text and files that are not too big to be unwieldy. At any rate, it is the responsibility of the students to make sure that the files they upload are readable and can be manipulated by Canvas without problems.

The official solutions will be distributed through Canvas right after the deadline. This policy implies that there can be no extensions to the homework deadline (nor can homeworks be made up).

Detailed instructions and advice on how to approach homework problems and how to present the solutions are given in Appendix B of this syllabus. The importance of homeworks should not be underestimated, since they serve as essential practice for the type of problems that will appear on the test. In other words the homeworks are an extension of instruction; they will contain examples that are useful for understanding the material and they will also cover some topics that follow naturally from the lectures but are not covered explicitly or in great detail in the lectures themselves.

Office Hours

The office hours are listed on the Home tab of this web site. They are intended for students to discuss with the instructor all matters related to this class, including (but not limited to) material covered in the class, the homework assignments, the tests, etc. Coming to office hours can be very beneficial as these can turn into tutorials on how to tackle problems on homeworks (hence, how to get ready for tests). In essence, they are an extension of instruction. Therefore, students are encouraged to make use of these office hours. 

To get the maximum benefit it is advisable to come prepared: attempt the homework problems first and bring your questions to the office hours. Of course, if you want to discuss how to initially approach a problem or understand what it is asking, those are legitimate and useful questions to ask and you should not hesitate to bring them with you to the office hours. You can also make strategic use of the two office hours available doing the week; for example, you can come to the first session and discuss clarifications and come again to the second session and discuss ore specific issues. See also the detailed advice on the Homework tab of this web site.

The Cardinal Rule

All students are responsible for knowing and following all the rules and regulations for this course as set forth in the syllabus (including any additional details on the class web site). Not knowing the rules is not an excuse for not following them. In case of any ambiguity, the instructor is the final arbiter. Students are also responsible for knowing what is announced in class.