In addition to the 12-inch refracting telescope, Kirkwood Observatory also houses a solar telescope used primarily as an instructional instrument. A heliostat on the roof of the Solar Laboratory reflects a beam of sunlight into the lab below, illuminating three mirrors on optical rails. One mirror projects a large, white-light image of the full Sun onto a wall screen, showing features on the Sun’s disk, including sunspots, plage, and limb darkening. A second mirror feeds sunlight into a spectrometer that projects the solar spectrum onto a viewing screen, showing the spectral colors and absorptions lines in the Sun’s spectrum. Finally, the third mirror passes sunlight through a very narrow band filter centered on the hydrogen-alpha spectral line, producing image of the Sun’s chromosphere, the layer of gas just above photosphere. The chromosphere image is displayed on a TV screen showing prominences, flares, and other active regions of the Sun.

Prevent eye damage! Do not look directly at the Sun.