Mighty 200-Inch Hale Telescope
In the late 1940s, a powerful new astronomical eye opened
at the Palomar Observatory in southern California. The 200-inch
Hale Telescope was twice as large as Mount Wilson's 100-inch
telescope and could collect four times as much light. It remained
the most powerful telescope in the world for over 30 years.
With the 200-inch telescope, astronomers could peer deeper
into the Universe than ever before and refine their estimates
of how fast the Universe is expanding.
instrument, called a spectrograph, combines the elements
of a spectroscope and a camera: it spreads the light from
a galaxy into a spectrum and records an image of that spectrum
photographically on a glass plate. It was custom-made for
mounting in the 200-inch telescope's prime focus cage, one
of several points on the telescope where observing instruments
can be attached. It was used for over 25 years.
With this spectrograph, the most sensitive available in the
early 1950s, coupled with the 200-inch telescope, the most
powerful in the world, astronomers were able to study the
faintest, most distant observable galaxies. Using the spectra
images it produced, they were able to measure the expansion
rate of the Universe with a precision never before possible.
Prime Focus Spectrograph designed by Rudolph Minkowski
and built by Don Hendricks in the Mount Wilson Optical Shop,
Donated by the California Institute of Technology,
Featured Artifacts in this section of the exhibit:
Lick Observatory Brashear
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