Hale Telescope mirror.. It was completed in 1948 and is still in active use. The Hale Telescope represented the technological limit in building large optical telescopes for over 30 years. It was the largest telescope in the world until the Russian BTA-6 was built in 1976, and the second largest until the construction of the Keck Observatory Keck 1 in 1993. Hale supervised the building of the telescopes at the Mount Wilson Observatory with grants from the Carnegie Institution of Washington: the telescope in 1908 and the telescope in 1917. These telescopes were very successful, leading to the rapid advance in understanding
Hale Telescope assigned the task of making a primary mirror. Construction of the observatory facilities and dome started in 1936, but because of interruptions caused by World War II, the telescope was not completed until 1948 when it was dedicated. Due to slight distortions of images, corrections were made to the telescope throughout 1949. It became available for research in 1950. The telescope saw first light on January 26, 1949 at 10:06pm PST under the direction of American astronomer Edwin Powell Hubble, targeting NGC 2261, an object also known as Hubble's Variable Nebula. The photographs made then were published in the astronomical