The C. Donald Shane telescope is a 120 inches (3.0 m) reflecting telescope located at the Lick Observatory in California. It was named after astronomer C. Donald Shane in 1978, who led the effort to acquire the necessary funds from the California Legislature, and who then oversaw the telescope's construction. It is the largest and most powerful telescope at the Lick Observatory, and was the 2nd largest telescope in the world when it was commissioned in 1959.[1]
The Shane's mirror started as a 10,000 lb Corning Labs glass test blank for the Palomar Observatory's 200 inch (5 m) Hale telescope (in southern California), but was sold below cost ($50,000 USD)[1] by Caltech to the Lick Observatory.[1] It was then transported to Mount Hamilton where the blank was ground and polished by the Observatory.[1]
Contents |
The Shane telescope is really three telescopes in one. It can be used in wide field prime focus, coudé focus for high precision spectroscopy, or the intermediate cassegrain focus.
In the Shane dome there is a laser, whose light is sometimes visible with the naked eye, that the observatory beams from the Shane telescope into the night sky. The laser is part of the Lick Adaptive Optics (LAO) program, a joint project of the Lick Observatory and the Lawrence Livermore National Laboratory. LAO corrects for atmospheric turbulence either by using a natural guide star or by creating a sodium laser guide star, and using the observed motion of the guide star to direct distortion of a deformable mirror hundreds of times each second. The system produces images that are nearly equivalent to those obtained from space-based telescopes. Adaptive optics using natural guide stars has been in development since 1996, and using laser guide stars since 2001. Similar laser adaptive optics systems based on LAO have been installed on the University of California's two Keck telescopes in Hawaii.
For Lick Obsevatory's first 55 years of operation, its astronomers relied on two telescopes built in the 19th century. Once considered giants in the field, they had become obsolete. International competition was mounting. The 120 inch reflector addition took 15 years to complete, being completed in 1959. It would be the second largest telescope in the World, taking its place behind the then enormous 200 inch Palomar Hale Telescope.
The Shane telescope saw first light to a different world for large telescopes in 1959:
| # | Name / Observatory |
Image | Aperture | Altitude | First Light |
Special advocate |
|---|---|---|---|---|---|---|
| 1 | Hale Telescope Palomar Obs. |
200 inch 508 cm |
1713 m (5620 ft) |
1948 | George Ellery Hale John D. Rockefeller |
|
| 2 | Shane Telescope Lick Observatory |
120 inch 305 cm |
1283 m (4209 ft) |
1959 | Nicholas Mayall C. Donald Shane |
|
| 3 | Hooker Telescope Mount Wilson Obs. |
100 inch 254 cm |
1742 m (5715 ft) |
1917 | George Ellery Hale Andrew Carnegie |
|
| 4 | Otto Struve Telescope McDonald Obs. |
82 inch 210 cm |
2,070 m 6791 ft |
1939 | Otto Struve |