# Assessment Instructions: Problem Set 01 — Stellar Properties, Spectra, and Classification

## Inputs to Inspect
Student submission, this problem set, the solution key, the corresponding lecture slides/notes, and the referenced dataset(s) under `materials/ASTR230/data/`.

## Grading Standard
Award credit for correct method and units first, then for the specific numeric result. A student who shows correct reasoning with a small arithmetic slip should receive most of the available credit; a student with a correct-looking number but no visible reduction steps should not.

## Problem-Level Criteria
- Problem 1: 15 points — Correct Stefan-Boltzmann luminosity for Rigel with units and visible arithmetic.
- Problem 2: 15 points — Correct flux ratio and correct identification of the brighter star.
- Problem 3: 15 points — Correct physical explanation referencing both ionization (hot end) and excitation (cool end).
- Problem 4: 15 points — Correct reproduction of the OpenStax worked radius-ratio method and a sensible numeric comparison.

## Resubmission Policy
Students may resubmit within one week of receiving feedback. A resubmission must show a corrected derivation, not only a corrected final number, and should reference the specific feedback comment it addresses. Regrade to a maximum of 90% of the original point value unless the error was a grading mistake.

## Common Errors to Flag
- Confusing luminosity ratio with flux (apparent brightness) ratio.
- Explaining Balmer line strength using composition ("more/less hydrogen") instead of ionization/excitation state.
- Missing units or unstated reference values (T_Sun, R_Sun) in Stefan-Boltzmann calculations.