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.

First Saturday Solar Viewing

Join us on the first Saturday of each month at Kirkwood Observatory. The Kirkwood Solar Telescope will be open for viewing from 1-3 PM, weather permitting, including special views of sunspots, the solar chromosphere, and prominences.