What can spectra tell us about temperature?
Stars are too far away (and too hot!) for a human to touch, yet we can measure their temperatures. Spectra make this possible! Let’s investigate how.Thermal Emission
Slideshow. This information about Thermal Emission can be reviewed as a class discussion, in small groups, or on your own, as instructed by your teacher.
Simulation.
OPTIONAL: Explore the PhET simulation on thermal (also known as "blackbody") spectra at the bottom of the page.
- Adjust the temperature on the thermometer to see how the spectrum changes as the temperature increases and decreases.
- Notice what colors in the visible spectrum are emitted for different temperatures. (The color the object would appear to you is approximated in the star-shaped icon next to the B, G, R symbols, above the spectrum graph.)
- Adjust the zoom levels of the x-axis (wavelength) and y-axis (brightness) as necessary.
