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.

Stars Part 2: Measuring Temperatures

Spectrum Tool. Using the Target Object menu, compare the spectrum of each star: Sun, M star, and B star. Using the Comparison Object menu, examine thermal spectra models for different temperatures (in Kelvin).

Spectrum Notebook. Answer this question in the table of the Spectra of Stars section:

  1. Comparing the spectrum of the star with the model spectra, what temperature thermal (blackbody) spectrum best matches the stars spectrum?

Note: The y-values of these model spectra are not plotted on the same scale—they have been modified so they can all be plotted in the range of the tool. The key is to compare the overall shape of the curves, and most importantly, where the peaks are.

Source 1:
 
Brightness
Full-intensity spectrum backgroundTransparency increases or decreases based on chart intensity, hiding or revealing the background
Left axis ticks
Spectrum intensity vs wavelength chart
Bottom axis ticks
Wavelength (Microns)
Source 2:
 
Brightness
Full-intensity spectrum backgroundTransparency increases or decreases based on chart intensity, hiding or revealing the background
Left axis ticks
Spectrum intensity vs wavelength chart
Bottom axis ticks
Wavelength (Microns)
part 1
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