Blackbody Radiation: Thermal Spectrum and Temperature

Name: ________________________________ Section: __________ Date: __________

Station: __________ Group members: ________________________________________________

Goal: Use the demo to make a claim supported by (1) at least one number/readout and (2) at least one sanity check.

Station card: Blackbody Radiation (6–8 minutes) Pick one preset (M dwarf, Sun, A/B star, or CMB) and record:

• Temperature $T$ (K)
• Peak wavelength $\lambda_{\text{peak}}$ (nm)
• Which band dominates (IR / visible / UV / microwave)

Then write one sentence:

“This star looks ____ because its blackbody peak is at ____.”

Word bank + sanity checks Word bank:

• Blackbody spectrum: the ideal “thermal glow” curve; temperature sets its shape.
• Temperature $T$ (K): hotter objects emit more and peak at shorter wavelengths.
• Peak wavelength $\lambda_{\text{peak}}$: where the curve is highest (the “peak marker”).

Key relationship (Wien scaling):

$$\lambda_{\text{peak}} \propto \frac{1}{T}$$

Sanity checks:

• Hotter → $\lambda_{\text{peak}}$ shifts to shorter wavelength (toward blue/UV).
• Cooler → $\lambda_{\text{peak}}$ shifts to longer wavelength (toward red/IR).
• In astronomy, “redder” blackbodies are cooler, not hotter.