A Visit to the Hale Solar Laboratory

Last Saturday I had the rare opportunity to visit the Hale Solar Laboratory. George Ellery Hale had the building built in 1924 to serve as his personal office and solar research lab after his retirement as the director of the Mount Wilson Observatory.

I took over 200 photos from my visit - far too many to share here, but I have included a few below.

The building is now privately owned, but it is a treasure. As you can see it was designated a National Historic Landmark in 1989.

Here is a diagram of the solar telescope contained within:


For our visit the solar telescope was brought back into action. Here is the view from within the dome:

The whole building is a 150-foot focal length folded telescope. Light from the Sun is collected by a coelostat mirror and reflected up to a second flat mirror which directs the light back down to a third mirror, back up to a "secondary" mirror and back down to the observing station seen below.
For spectrographic work the light is further directed down in the a deep pit and through a diffraction grating. Here's a look taken from partway in the pit looking upward.

The observing station and Hale's library (below) may look familiar to you if you have seen the documentary about Hale, The Journey to Palomar.

Much of Hale's writings about astronomy in the mid to late 1920s and his planning for the 200-inch telescope took place here in this room. I feel fortunate to finally have had the chance to visit Hale's Fortress of Solitude.