Problem set for lecture unit 4.
A raw light frame reads 22,000 ADU at a given pixel; the matched-exposure master dark (bias-inclusive) reads 460 ADU at that pixel, and the normalized flat-field value there is 0.97. Compute the calibrated ADU value at this pixel using I_cal=(raw-D)/F.
A second Landolt-type standard star has V=7.861 and is measured at a count rate of 735081.014 e⁻/s on the same photometric night as Lab 04's SA 98-978. Solve for the zero point Z_pt implied by this second star alone.
Compare your Problem 2 zero point to the zero point derived from SA 98-978 in Lab 04, and state whether the two are consistent to within a few hundredths of a magnitude (as expected on a genuinely photometric night) or suggest a possible calibration problem.
If the two zero points disagreed by several tenths of a magnitude rather than a few hundredths, list two specific, physically distinct calibration or observing problems (e.g., non-photometric conditions, a flat-field or dark-subtraction error) that could explain such a discrepancy, and explain how an observer would distinguish between them.
Submit a complete derivation with equations, units, labeled quantities, and a short narrative interpretation for each problem. Show every step; a correct final number without a visible derivation receives partial credit at most, and quoting a lecture number without adapting it to this problem's specific inputs receives no credit for that step.
OpenStax Astronomy 2e (local reference copy: references/openstax-astronomy-2e-extracted.txt), Chapter 6 (astronomical instruments), descriptive only; this course exceeds that introductory treatment throughout.
materials/ASTR340/data/ where referenced above.