# Assessment Instructions: Problem Set 03 — The pp-Chain/CNO Crossover Temperature for Alpha Centauri A

## Inputs to Inspect
Student submission, this problem set, the solution key, the corresponding lecture slides/notes, and the referenced dataset(s) under `materials/ASTR330/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 derivation steps should not. Because this is a 300-level quantitative course exceeding ASTR 310's own rigor, full marks require a genuine derivation (not just formula substitution) wherever the problem set asks for one.

## Problem-Level Criteria
- Problem 1: 20 points — correct exponent application and T6 conversion.
- Problem 2: 15 points — correct Gamow-peak arithmetic and comparison.
- Problem 3: 15 points — correct classification with supporting reasoning.
- Problem 4: 20 points — correct quantitative use of the T6²⁰ sensitivity, not just a qualitative statement.

## 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
- Forgetting to raise the temperature ratio to the 0.7 power (schematic mass-scaling relation) before comparing stars.
- Treating the crossover temperature as an exact reaction-network result rather than a schematic power-law approximation.
- Giving only a qualitative answer to Problem 4 without the required T6²⁰ quantitative reasoning.