Trying to find concepts and lessons to teach has actually gotten me a little bit more interested in the subject. I became curious as how how exactly do Astronomers use spectra to learn about the Sun and other stars. It turns out that a lot can still be taught about the Sun that isn’t too “disconnected from general knowledge.”
Every different ion of an element sends out light at combinations of wavelengths that are unique. Light at these wavelengths, known as emission lines, can be used like fingerprints to identify the atom or ion that sent out the light. And because ions of an element are particularly selective in their temperature ranges, each ion of an element can only exist at certain temperatures unique to each ion of the element. With these facts, astronomers can tell which elements and ions exist on a star, and the temperature at that location on the star.
In addition to reading the wavelength combinations, astronomers can also utilize the Doppler Effect to determine the movement of a star (or object) in space. If the wavelength of an emitting source is shorter than it’s resting wavelength, then the source is approaching us. If the wavelength of an emitting source is longer than it’s resting wavelength, then the source moving away from us. [The question I have is, how do astronomers determine the resting wavelength of an emitting source if the source is in motion? ]
These concepts are definitely graspable for high-schoolers, and could likely be demonstrated to middle-schoolers without too much difficulty. If we ever do have a teacher’s manual, we could definitely add these concepts and create lesson plans accordingly.
In between study/learning sessions, I worked a bit on our Powerpoint presentation for the Intern Symposium. The Powerpoint is near complete, and it only needs a few more slides and a few visuals that I have saved on my home desktop. Overall, I’m pretty content with the content of our Powerpoint!