Corning Incorporated has completed the sagging process of the 4.2-meter ULE(R) mirror blank that will serve as the primary mirror for Lowell Observatory“s Discovery Channel Telescope, the company sai…
Corning Incorporated has completed the sagging process of the 4.2-meter ULE(R) mirror blank that will serve as the primary mirror for Lowell Observatory“s Discovery Channel Telescope, the company said 22 June 2005. Corning“s proprietary ULE(R) is a glass material which exhibits virtually no dimensional changes over extreme temperature variations. This material is generally considered to be one of best in the world for astronomical optics, according to Corning. The sagging process consisted of creating a form made of refractories that meet the concave-convex shape requirements of mirror designers. The ULE mirror blank was positioned over the form and heated to approximately 1482 degrees Centigrade to attain the material“s softening point. At this point, the blank began to sag around the refractories and conformed to the specifications of the mirror designers. Danny Henderson, division vice president and business director, Corning Specialty Materials said, “Corning is very proud to have been selected the material supplier for the DCT mirror. The successful completion of the sagging milestone can be attributed to Corning“s wealth of experience in supplying astronomy ULE mirrors and the excellent performance of the team in Canton, NY. We are now proceeding to the next phase of the program, the net grinding of the mirror blank. Corning looks forward to working closely with Discovery Communications and Lowell Observatory through completion of the DCT mirror.” The Discovery Channel Telescope (DCT) will be located at a new site being developed by Lowell Observatory on the Coconino National Forest in northern Arizona. When completed, it will be the fifth largest telescope in the continental United States. The DCT has a unique optical configuration that allows it the ability to focus on a wide field or to be switched to a longer focal length. This attribute greatly exceeds the capabilities of today“s existing telescopes of the same class. The DCT, in a single wide field exposure mode, will allow astronomers to survey an area of the sky equal to the size of 16 full moons. In the longer focal length mode, the DCT will allow astronomers to zoom in on selected objects for detailed observation and subsequent analysis.