Description
Introduces stellar properties, stellar evolution, the interstellar medium, the Milky Way, galaxy classification, galaxy evolution, large-scale structure, dark matter, dark energy, and the observational foundations of modern cosmology. Quantitative reasoning builds on ASTR 101's introductory survey and on the mechanics and electromagnetism developed concurrently in PHYS 171, using algebra-and-trigonometry-level physics (no calculus is required, though students concurrently in PHYS 171 will see the same force and energy concepts from a calculus-based perspective).
Learning Outcomes
- Derive and apply the physical relationships among stellar luminosity, temperature, radius, and distance (Stefan–Boltzmann law, inverse-square law, distance modulus, parallax) to real stellar data.
- Explain the physical basis of stellar spectral classification and construct and interpret Hertzsprung–Russell diagrams for real star samples and clusters.
- Trace the evolutionary path of low-mass and high-mass stars from the interstellar medium through the main sequence to white dwarfs, neutron stars, and black holes, with quantitative mass-luminosity and mass-radius reasoning.
- Describe the structure of the Milky Way and the observational evidence (rotation curves, velocity dispersions) for dark matter.
- Classify galaxies using the Hubble tuning fork and connect galaxy morphology to stellar populations, gas content, and evolutionary history, including galaxy interactions and active galactic nuclei.
- Apply Hubble's law to redshift-distance data to estimate the age and expansion history of the universe, and summarize the observational case for dark energy and large-scale cosmic structure.
Textbook and Materials
Primary reading: OpenStax Astronomy 2e (free, openly licensed; local extracted reference copy under references/openstax-astronomy-2e-extracted.txt and problem index under references/source-indexes/), Chapters 15–29 (The Sun through The Big Bang). Chapter/section citations in lecture notes and problem sets use the OpenStax Astronomy 2e native chapter numbering (verified against the local extracted text; the generated problem index under references/source-indexes/ uses an internal numbering offset by −1 relative to the published edition—always cite the native chapter number, e.g. Chapter 18 for “The Stars: A Celestial Census,” not the index's internal chapter label).
Assessment
| Component | Weight |
|---|---|
| Problem sets (7) | 30% |
| Labs (7) | 30% |
| Midterm exam (Lectures 1–7) | 15% |
| Final exam (cumulative, emphasis Lectures 8–14) | 20% |
| Participation and reading checks | 5% |
Lecture, Lab, and Problem-Set Cadence
The course runs 14 lectures, 7 labs, and 7 problem sets — a matched 1:1 biweekly cadence in which each lab and its paired problem set both follow the same two-lecture unit, so students immediately apply a unit's quantitative tools to a hands-on data set (the lab) and to independent numeric problems (the problem set) before the next unit begins. This mirrors the biweekly structure used in ASTR 101 and ASTR 120 rather than ASTR 210's specialized capstone-synthesis cadence, because ASTR 230's units introduce a new physical regime (stellar structure, then stellar death, then galaxies, then cosmology) every two lectures rather than building toward a single technical report.
| Unit | Lectures | Lab | Problem Set | Topic |
|---|---|---|---|---|
| 1 | 1–2 | Lab 01 | PS 01 | Stellar properties, spectra, and classification |
| 2 | 3–4 | Lab 02 | PS 02 | Distances, magnitudes, and stellar structure/energy generation |
| 3 | 5–6 | Lab 03 | PS 03 | Star formation, the ISM, and post-main-sequence evolution |
| 4 | 7–8 | Lab 04 | PS 04 | White dwarfs, supernovae, and neutron stars |
| 5 | 9–10 | Lab 05 | PS 05 | Black holes and the Milky Way's rotation curve/dark matter |
| 6 | 11–12 | Lab 06 | PS 06 | Galaxy classification, AGN, and galaxy evolution |
| 7 | 13–14 | Lab 07 | PS 07 | Large-scale structure and observational cosmology |
Revision Policy
High standards apply to all graded work. Problem sets and labs may be revised and resubmitted once for improved credit within one week of return, provided the resubmission includes a short change note identifying what was corrected and why (see each problem set's assessment instructions for full criteria).
Prerequisites Check
ASTR 101 provides the descriptive foundation (celestial sphere, light, telescopes, a first look at stars/galaxies/cosmology) that ASTR 230 makes quantitative. PHYS 171 (or concurrent enrollment) supplies Newtonian mechanics, energy, and momentum, used here for orbital and escape-velocity reasoning (binary stars, black holes) and for the physics of radiation pressure and gravitational collapse in star formation.