Revolutionary New Hobby-Eberly Telescope

October 03, 1997

A joint release from the University of Texas at Austin; Pennsylvania State University (Penn State); Stanford University; Georg-August University in Goettingen, Germany, and Ludwig-Maximilians University in Munich, Germany.

Mount Fowlkes near Fort Davis, Texas--The Hobby-Eberly Telescope represents a new era in the design and construction of telescopes. It is the first modern large optical telescope to use an innovative, cost-saving fixed-mirror design. It is also the first telescope ever designed and built to be optimized for spectroscopic surveys of the sky.

The primary mirror of the Hobby-Eberly Telescope is composed of 91 separate one-meter (39.37 inch) hexagonal mirrors, aligned by small computer-controlled motors to act as a single 11-meter (433-inch) light-gathering surface. The light-gathering power of large telescopes is determined by the area of their primary mirrors. The Hobby-Eberly Telescope will be able to gather light from objects close to 100 million times fainter than the unaided human eye can see.

Because of the way the Hobby-Eberly Telescope will be used, 9.2 meters (362 inches) of its surface will be accessible at any given time. Thus, the Hobby-Eberly Telescope is effectively the third-largest telescope in the world, after the twin 10-meter (393-inch) Keck I and Keck II telescopes in Hawaii.

Based on a modification of the concept used in the large radio telescope at Arecibo in Puerto Rico, the Hobby-Eberly Telescope has a primary mirror that does not move up and down from the horizon to the zenith to track stars as they move across the sky, as the primary mirrors of most telescopes do. The Hobby-Eberly Telescope is set in place to point at a given area of the sky prior to an observation period. A much lighter tracker assembly, mounted at the top of the telescope above the primary mirror, then moves to track the astronomical object being observed. Exposure times on a given object of up to two-and-a-half hours are possible.

The innovative design and the use of cost-effective, off-the-shelf technology made it possible to construct the Hobby-Eberly Telescope for a total price of $13.5 million. This is only a fraction of the cost of each of the only comparable telescopes in the world, the twin Keck I and Keck II telescopes in Hawaii. The fixed-mirror design of the Hobby-Eberly Telescope means that it cannot be pointed close to the horizon or the zenith, but scientists using it will be able to cover 70 percent of the sky available above McDonald Observatory over the course of a year, providing first-class scientific capability at a bargain price.

The Hobby-Eberly Telescope is designed to make substantial contributions to many areas of astronomical research. For example, astronomers will measure the chemical compositions of stars that were too distant to study previously, search for planets in orbit around distant stars, identify and measure activity on the surfaces of stars, learn more about "dark matter" located around galaxies, monitor violent activity in the hearts of some galaxies, and refine theories about star formation and evolution.

The Hobby-Eberly Telescope's primary mirror is curved in the shape of a partial sphere, so each of the Hobby-Eberly Telescope's mirror segments is identical in shape and curvature. They were produced by the same assembly-line method and any segment can be used to replace any other, a key cost-saving aspect of the telescope. Spherical mirrors do not produce images as sharp as those produced by the parabolic mirrors found in other telescopes. For this reason, the Hobby-Eberly Telescope uses a "spherical aberration corrector" that allows it to make sharp images over a small area. Light is transmitted from the spherical aberration corrector through fiber-optic cables to spectrographic instruments located in a temperature-controlled room beneath the telescope, where the spectra can be captured for later analysis by computer.

The Hobby-Eberly Telescope stands on Mount Fowlkes at McDonald Observatory, adjacent to Mount Locke, the site of McDonald Observatory's other research telescopes. McDonald Observatory, in far West Texas, has the darkest skies of any major observatory in North America. A new gallery, which will allow visitors a close-up view of the new telescope, will open in December, 1997. Currently more than 120,000 visitors per year visit McDonald Observatory. That number is expected to double in the next five years. McDonald Observatory is expanding its visitors' center facilities to keep pace with growing public interest.

Ground-breaking for the Hobby-Eberly Telescope occurred in March of 1994. "First light," the first engineering proof that the telescope works, was achieved in December 1996. "First Spectrum," the demonstration that the telescope and its commissioning instrumentation package work as planned, occurred in early September 1997, as did the initiation of limited regular scientific use of the telescope. The telescope is currently in its "commissioning" phase, similar to a "shake-down" cruise for a ship, in which its components are brought into optimal performance. The final instrumentation packages for the telescope are being constructed elsewhere and are expected to be installed throughout 1998.

Editor's Note:
A free and unrestricted satellite news feed of the Hobby-Eberly Telescope dedication will be available on Wednesday, October 8, 1997 from 9:30 a.m. to 11:00 a.m. Central Daylight Time. The news feed will include b-roll and interviews, followed by live dedication coverage. Coordinates for the satellite news feed are: Telstar 5 (Ku) 97 degrees West; Transponder 12, Horizontal, full; 11,935.5 Megahertz; Audio 6.2 6.8. On-site engineer is Ray Guy (telephone 512/415-9863).

High-resolution images of the Hobby-Eberly Telescope and a 21-page press kit about the dedication with background information on the telescope's cost-saving design, are available for downloading over the Internet at <> and at<>.

To obtain a copy of the press kit by mail or fax, call Joel Barna at 512/471-6335 or Delores Baldwin at 512/471-3303.

The William P. Hobby-Robert E. Eberly Telescope, which contains the world's largest primary mirror, and which was built for a fraction of the cost of other comparable telescopes, will be formally dedicated October 8 during a ceremony at McDonald Observatory in the Davis Mountains of far West Texas.

The Hobby-Eberly telescope was built by a partnership of five universities: the University of Texas at Austin; Pennsylvania State University (Penn State); Stanford University; and two German universities, Georg-August University in Goettingen and Ludwig-Maximilians University in Munich. Representatives of each of the partner institutions will speak at the dedication. Nobel-prize-winning physicist Steven Weinberg will deliver the dedication keynote address.

The namesakes of the Hobby-Eberly are Bill Hobby, the former Lieutenant Governor of Texas, and Robert E. Eberly of Pennsylvania, an industrialist and philanthropist.
Joel W. Barna
Development Manager
McDonald Observatory
512/471-6335 fax 512/471-6016

Penn State

Related Telescope Articles from Brightsurf:

ATLAS telescope discovers first-of-its-kind asteroid
University of Hawai'i telescope discovers extraordinary asteroid with comet-like features that has researchers puzzled.

Precision calibration empowers largest solar telescope
An article published in the SPIE publication Journal of Astronomical Telescopes, Instruments, and Systems (JATIS), 'Polarization Modeling and Predictions for DKIST Part 5: Impacts of enhanced mirror and dichroic coatings on system polarization calibration,' marks a substantial advance in ensuring the accurate solar information measured and collected by the Daniel K.

Subaru Telescope captures 1800 exploding stars
The Subaru Telescope has captured images of more than 1800 exploding stars in the Universe, some located 8 billion light years from Earth.

Quasar jets confuse orbital telescope
Astrophysicists from the Moscow Institute of Physics and Technology, the Lebedev Physical Institute of the Russian Academy of Sciences (LPI RAS), and NASA have found an error in the coordinates of active galactic nuclei measured by the Gaia space telescope, and helped correct it.

Cosmic telescope zooms in on the beginning of time
Observations from Gemini Observatory identify a key fingerprint of an extremely distant quasar, allowing astronomers to sample light emitted from the dawn of time.

Both halves of NASA's Webb Telescope successfully communicate
For the first time, the two halves of NASA's James Webb Space Telescope -- the spacecraft and the telescope -- were connected together using temporary ground wiring that enabled them to 'speak' to each other like they will in flight.

Balloon-borne telescope looks for cosmic gamma rays
Cosmic gamma rays can provide us with important insights into the high-energy phenomena in our universe.

Natural telescope sets new magnification record
An international team of astronomers, led by Harald Ebeling of the Institute for Astronomy at the University of Hawaii at Manoa, has discovered one of the most extreme instances of magnification by gravitational lensing.

NASA's Webb Telescope to witness galactic infancy
Scientists will use NASA's James Webb Space Telescope to study sections of the sky previously observed by NASA's Great Observatories, including the Hubble Space Telescope and the Spitzer Space Telescope, to understand the creation of the universe's first galaxies and stars.

New way to weigh a white dwarf: Use Hubble Space Telescope
For the first time, astronomers have used a novel method to determine the mass of a type of star known as a 'white dwarf' -- the shrunken corpse of a dead star that used to be like our sun.

Read More: Telescope News and Telescope Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to