1. Combined uncertainty
σ_total = √(0.03² + 0.02²) = √(0.0009 + 0.0004) = 0.036 mag.
| Criterion | Points |
|---|---|
| Quadrature method | 8 |
| Correct value | 7 |
Worked Solutions
2. Claim strength critique
SNR = 4.2 falls in the marginal range (3–5), not the secure range (≥ 5), so "definitive detection" overstates the evidence. Better wording: "a marginal detection (SNR ≈ 4.2) that should be confirmed with additional observations."
| Criterion | Points |
|---|---|
| Correct classification | 8 |
| Reasonable revised wording | 7 |
3. Report-section sorting
(a) Methods. (b) Limitations. (c) Results.
| Criterion | Points |
|---|---|
| All three correctly sorted | 15 |
4. Final synthesis
Example: "The target’s calibrated magnitude is 14.02 ± 0.04 mag, combining zero-point and instrumental uncertainty in quadrature; this result assumes the comparison-field zero point remained stable throughout the night, which was not independently verified beyond this single observing session."
| Criterion | Points |
|---|---|
| Correct measurement and uncertainty stated | 8 |
| Explicit, reasonable limitation stated | 7 |
Grading Notes
Award full marks for correct method, units, and a numeric result consistent with the arithmetic shown (allow reasonable rounding). Common partial-credit errors: omitting units, failing to combine uncertainties in quadrature, or overstating the confidence of a marginal (SNR 3–5) result.