05/02/1996 07:00:00

Keck II Telescope to Be Dedicated

PASADENA—The 10-meter Keck II Telescope will be dedicated in a mountaintop ceremony at 11:00 a.m. (Hawaiian Time) on Wednesday, May 8. Keck II and its five-year-old twin Keck I are the world's largest optical telescopes.

Edward C. Stone, director of NASA's Jet Propulsion Laboratory and chair of the board of directors of the California Association for Research in Astronomy (CARA), which owns and operates the telescopes, will lead the ceremony inside the Keck II dome on the summit of Mauna Kea, a 13,796-foot dormant volcano on the Big Island of Hawaii.

Following a traditional dedication chant by Hawaiian elder Kepa Maly, the audience will hear brief remarks from University of Hawaii President Kenneth P. Mortimer, California Institute of Technology President Thomas E. Everhart, University of California President Richard C. Atkinson, NASA chief scientist France Córdova, and Keck Foundation chairman and president Robert A. Day.

Clair W. Bergener, chair of the University of California Regents, and Gordon E. Moore, chair of the California Institute of Technology's Board of Trustees, will then make a joint presentation to Howard B. Keck, who served as the W. M. Keck Foundation's chairman and president for more than 30 years. The Keck Foundation has provided more than $150 million toward funding the telescopes.

As a finale, Stone will take the telescope for a spin, briefly demonstrating how the telescope and dome move. Although it weighs nearly 300 tons, the telescope is so precisely balanced that, with the brakes released, a person could move it by pushing with one hand. Keck II is presently operational for engineering tests and has taken a few astronomical images; it will be fully operational for science in October.

The Keck II Telescope, like its sibling Keck I, uses a mirror composed of 36 hexagonal pieces of glass, individually polished and assembled to form a perfectly parabolic reflecting surface with an effective diameter of 10 meters, or nearly 33 feet. This segmented mirror is much thinner, and therefore lighter in weight, than a solid mirror could be, which is the key to building such a large instrument.

In addition to doubling the amount of observing time available at the Keck Observatory, Keck II will allow a wider array of observing instruments to be used. Scientists have designed and are building three specialized spectrographs—instruments for recording an object's spectrum—for use on Keck II that will make possible an observational program with great flexibility and range.

The Near-Infrared Spectrograph will be able to record spectra from extremely faint objects at wavelengths just slightly longer than are visible to the human eye. DEIMOS, a powerful multi-object spectrograph, will be able to record spectra from up to 100 objects simultaneously. And the Echelle Spectrograph and Imager will have the ability to record a spectrum over an extremely broad range of wavelengths. These, together with the instruments of Keck I, are arguably the finest astronomical instruments in the world. Together, they allow each astronomer to customize his or her observations to suit the astronomer's individual needs.

Keck II will also have an adaptive optics facility that will enable it to produce images with a resolution of 0.04 arc seconds at a wavelength of 2 microns. Adaptive optics is a method of compensating for the slight distortions caused by atmospheric turbulence. People see distorted starlight as twinkling, but for a telescope making a long exposure, turbulence makes the star look slightly blurry. The adaptive optics system will be able to detect these atmospheric distortions and make one hundred tiny adjustments to the mirror per second to compensate for them and maintain the sharpest possible image.

In the long term, Keck I and Keck II have the potential to work together as an interferometer—a system in which light from one telescope is combined and interferes with light from the other telescope. Scientists can extract extremely high-resolution images from this interference. Because Keck I and Keck II are some 85 meters (nearly 280 feet) apart, they would have a resolution equivalent to a telescope with an 85-meter mirror, or about 0.005 arc seconds at a wavelength of 2 microns.

SATELLITE BROADCAST: Feed Date: May 8, 1996 Feed Time: 10:45 a.m. to 12:15 p.m. Hawaiian Time 4:45 p.m. to 6:15 p.m. Eastern Time Coordinates: Satellite Galaxy K4, Transponder 11, Channel 51 Downlink frequency 11915 MHz V

IMAGES AVAILABLE: Three of the first space images taken with the Keck II Telescope are available through Andy Perala at the Keck Observatory, through Reuters, Agence Presse France, and UPI, and, for AP Photo Members only, through Photostream.

Captioned photos of the twin Keck Telescopes are available from the above sources, and from Jay Aller and Max Benavidez at Caltech.