1. Stacking gain 15 points
A single exposure gives SNR = 15. Compute the expected SNR after stacking 16 independent, registered exposures.
Problems
2. Cosmic-ray bias in a mean combine 15 points
One frame out of 16 contains a cosmic-ray spike of 8000 counts in the target pixel. Compute the bias this introduces into a simple mean combine of all 16 frames.
3. Cadence adequacy 15 points
An event lasts 3.4 hours. A proposed cadence images the field every 45 minutes. Compute how many samples this cadence captures across the event and judge whether that is adequate to resolve ingress, minimum, and egress.
4. Nyquist-style check 15 points
A periodic signal has period 5.2 hours. A 6-hour cadence is proposed. Determine whether this cadence can recover the signal, and propose a cadence (such as 1 hour) that would.
Due and Scope
Submit a clear solution with equations, units, labeled quantities, and a short narrative interpretation for each problem. Show every reduction step and state your assumptions explicitly; a correct final number without visible work receives partial credit at most.
OpenStax Companion Reading
Verify against OpenStax Astronomy 2e Chapter 6.3 (detectors) and Chapter 19.3 (variable stars, cadence) before instructional release.
References and Data Sources
- Corresponding lecture slides and notes for this unit.
- OpenStax Astronomy 2e (local reference copy: references/openstax-astronomy-2e.pdf).
- Course datasets under
materials/ASTR210/data/where referenced above.