ASTR-5700, Spring 2026

Instructor:	Steven R. Cranmer   (email, web page)
Instructor's Office:	Duane Physics D111 (main campus), LASP/SPSC N218 (east campus)
Course Times:	Spring 2026, Mon./Wed./Fri., 9:05-9:55 am
Location:	Duane Physics, Room E126
Office Hours:	TBD dates, times, and modes (in-person or virtual)
Syllabus:	See the most up-to-date PDF version.

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Summary

Stars are the basic building blocks of the universe, and they are responsible for the production of most elements via nucleosynthesis. In this course, we will explore the physical principles that govern stellar interiors, evolution, and atmospheres, with the Sun and its heliosphere often being used as the closest and best-studied example of a star. The course will cover energy generation and transport in stars, principles of stellar structure, stellar rotation, pulsation, and evolution up to supernova and compact object stages. The course will also include radiation transport in stellar atmospheres, and (if there is time) the physics of chromospheres, coronas, and winds. We will occasionally touch on topics in planetary science, especially in areas where the boundary lines between stars, brown dwarfs, and planets become somewhat ambiguous.

This course is an elective for APS graduate students. Strongly recommended pre-requisites include upper-level undergraduate astrophysics and E&M. The catalog says that a recommended pre-requisite or co-requisite is Radiative and Dynamical Processes (ASTR-5120), but I won't assume that students have taken it.

Course Material

The primary "required readings" are my lecture notes, which will be posted on Canvas as the semester progresses. Other resources for this course include:

• A list of other online books and lecture notes that supplement my own material.
• Handout: useful math/physics formulae & constants that you're free to use for any work in this course (revised for Spring 2026).
• Soon, we will post detailed guidelines for the final project (papers and poster session).

Schedule

Below is a detailed schedule that will list the material covered in each class session and various course deadlines. A more detailed "after-the-fact" class-by-class schedule will be updated and maintained on Canvas.

1. Fri., January 9: Introductory overview; syllabus summary. Begin overview of stellar observations and the H-R Diagram.
   • Homework 1 assigned, due Fri., January 23.

2. Mon., January 12: Continue overview of stellar observations and the H-R Diagram.

3. Wed., January 14: Kinetic and thermodynamic properties of gases (relevant to stars).

4. Fri., January 16: Kinetic and thermodynamic properties of gases (relevant to stars).

   [Mon., January 19: Martin Luther King Holiday; no classes.]

5. Wed., January 21: Kinetic and thermodynamic properties of gases (relevant to stars).

6. Fri., January 23: Kinetic and thermodynamic properties of gases (relevant to stars).
   • Homework 1 due.
   • Homework 2 assigned, due Wed., February 4.

7. Mon., January 26: Stellar energy sources, including gravitational contraction and the virial theorem.

8. Wed., January 28: Stellar energy sources, including nuclear energy generation.

9. Fri., January 30: Stellar energy sources, including nuclear energy generation.

10. Mon., February 2: Stellar energy sources, including nuclear energy generation.

11. Wed., February 4: Stellar energy sources, including nuclear energy generation.
    • Homework 2 due.
    • Homework 3 assigned, due Wed., February 18.

12. Fri., February 6: Energy transport from core to surface: radiation and convection.

13. Mon., February 9: Energy transport from core to surface: radiation and convection.

14. Wed., February 11: Energy transport from core to surface: radiation and convection.

15. Fri., February 13: Energy transport from core to surface: radiation and convection.

16. Mon., February 16: Spherical stellar model interiors.

17. Wed., February 18: Spherical stellar model interiors.
    • Homework 4 due.
    • Take-home Midterm Exam assigned (see Canvas), due Wed., February 25.

18. Fri., February 20: Spherical stellar model interiors.

19. Mon., February 23: Spherical stellar model interiors.

20. Wed., February 25: Non-spherical effects: rotation (maybe tides, dynamos, pulsations).
    • Take-home Midterm Exam due.
    • Homework 4 assigned, due Wed., March 11.

21. Fri., February 27: Non-spherical effects: rotation (maybe tides, dynamos, pulsations).

22. Mon., March 2: Star formation and the interstellar medium.

23. Wed., March 4: Star formation and the interstellar medium.

24. Fri., March 6: Star formation and the interstellar medium.

25. Mon., March 9: Pre-main-sequence stellar evolution.

26. Wed., March 11: Pre-main-sequence stellar evolution.
    • Homework 4 due.
    • Homework 5 assigned, due Wed., April 1.

27. Fri., March 13: Pre-main-sequence stellar evolution.

    [March 16-20: Spring Break; no classes.]

28. Mon., March 23: Main-sequence and post-main-sequence stellar evolution.

29. Wed., March 25: Main-sequence and post-main-sequence stellar evolution.

30. Fri., March 27: Main-sequence and post-main-sequence stellar evolution.

31. Mon., March 30: Main-sequence and post-main-sequence stellar evolution.

32. Wed., April 1: Stellar death: supernovae and compact objects.
    • Homework 5 due.

33. Fri., April 3: Stellar death: supernovae and compact objects.

34. Mon., April 6: Stellar death: supernovae and compact objects.

35. Wed., April 8: Radiative transfer and stellar atmospheres.

36. Fri., April 10: Radiative transfer and stellar atmospheres.

37. Mon., April 13: Radiative transfer and stellar atmospheres.

38. Wed., April 15: Non-LTE processes in stellar atmospheres and spectral lines.

39. Fri., April 17: Non-LTE processes in stellar atmospheres and spectral lines.

40. Mon., April 20: Brief overview of stellar winds and mass loss.

41. Wed., April 22: Brief overview of stellar winds and mass loss.

42. Fri., April 24: Final project poster session!
    • Due date for final project papers: TBD.

    [April 25-26: End of Term Reading Days. April 27-May 1: Final Exam Week.]