Observatory case file 10-A

Starlight
Detective

Every beam of starlight is evidence. Focus the instrument, match spectral fingerprints, measure motion, read a blackbody curve, and identify a mystery star.

Class identifier Use the identifier your teacher expects. Avoid entering your full name.

About 12 minutes • Touch, mouse, or keyboard • Pass 4 of 5 checks for a verified badge

01FocusReveal the signal
02FingerprintIdentify matter
03MotionMeasure a shift
04HeatFit the curve
05VerdictClassify the star

TEKS 112.48(10A), (13A), and (13E)

Spectral field notes

A hot, dense source produces a continuous spectrum. Cooler gas in front of it absorbs specific wavelengths, leaving dark lines.
Each element has a distinctive set of spectral lines because its electrons exchange energy in specific amounts.
Lines shifted toward longer, redder wavelengths indicate recession; shifts toward shorter, bluer wavelengths indicate approach.
A blackbody's peak wavelength moves toward blue as temperature increases. Real stars are close to blackbodies but also show absorption lines.
Temperature alone does not determine luminosity. A cool giant can outshine a much hotter but tiny white dwarf.

NASA Science: Stars NASA: The Electromagnetic Spectrum OpenStax: Spectroscopy in Astronomy

StarlightDetective

Spectral Sleuth

Starlight
Detective