Hobby-Eberly Telescope Enters Early Operation Phase

Mount Fowlkes near Fort Davis, Texas: The Board of Directors of the William P. Hobby-Robert E. Eberly Telescope (HET) declared in October that the commissioning phase for the innovative telescope in West Texas had ended, and that the early operations phase had begun.

"Early operations marks the beginning of regular use of the HET for science," says Frank Bash, chairman of the Hobby-Eberly Telescope Board, director of McDonald Observatory, and the Frank N. Edmonds, Jr., Regents Professor in Astronomy at the University of Texas at Austin. "This is an important milestone for an unique and powerful new scientific instrument, and we want the astronomical community to know about it."

"Scientists at all institutions participating in the HET have been eagerly anticipating the flow of astronomical data that early operations are now producing. Indeed, the HET is already paying scientific dividends by making contributions in the areas for which it was designed: spectroscopic surveys and time-domain astrophysics," says Larry Ramsey, the HET project scientist and professor of astronomy and astrophysics at Penn State. Ramsey is is one of the original designers of the HET concept, along with Daniel Weedman, formerly at Penn State and now at the National Science Foundation Division of Astronomical Science."

Adds Thomas G. Barnes III, associate director of McDonald Observatory, who led the commissioning team, "We are especially delighted that the early weeks of operations for the telescope have yielded exciting results that hint at the kind of capability the telescope will have when it is in full operation."

The HET contains the world's largest primary mirror, measuring 11 meters (433 inches) from edge to edge. Due to its innovative design, the HET was built and commissioned for $15 million, a fraction of the cost of other comparable telescopes. The HET was constructed and is operated by a consortium 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.

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.

The HET attained "first light" in December 1996 and "first spectrum" in September 1997. It was dedicated in October 1997. The telescope's commissioning phase, during which the telescope's sophisticated optical, mechanical, and electrical systems were de-bugged, integrated, and optimized for science operations, lasted until October 1999. In early operations, the telescope will be used for scientific research for half of each month. So far, the telescope is operating with the Marcario Low-Resolution Spectrograph, designed and built by a team led by Gary Hill and Phillip MacQueen of McDonald Observatory, and the Upgraded Fiber Optic Echelle spectrograph, an instrument built at Penn State by Larry Ramsey and Penn State graduate students Jason Harlow and David Andersen. A high-resolution spectrograph, designed and built by a team led by Robert Tull of McDonald Observatory, will be installed in early 2000, to be followed by a medium-resolution spectrograph, being constructed under the direction of Larry Ramsey.

Users of the HET report exciting results. The first paper based on observations with the HET was recently accepted by the Publications of the Astronomical Society of the Pacific and will appear in the January 2000 issue. Donald Schneider, professor of astronomy and astrophysics at Penn State; Gary Hill, of Texas; and Xiaohui Fan, a graduate student at Princeton University, have led a project to obtain HET spectra of high-redshift quasar candidates found by the Sloan Digital Sky Survey (SDSS). During this past spring, five quasars with redshifts between 2.9 and 4.2 were discovered by observations with the LRS. This work has continued through the fall, and the HET has observed more than a dozen distant quasar candidates in the past few weeks.

Edward L. Robinson, the William B. Blakemore II Regents Professor in Astronomy at the University of Texas at Austin, has used the HET to observe a new X-ray star in visible light. The X-ray properties of the new star, named J1859+226, show that it is probably a black hole that has begun to swallow gas pulled off a normal star orbiting around the black hole.

New X-ray stars, called X-ray transients, are rare. About one X-ray transient erupts per year in our galaxy. J1859+226 erupted a week after the beginning of Early Operations on the HET. Because objects observed with the HET are chosen dynamically and in real time (the HET is "queue scheduled"), Robinson was able to begin observing J1859+226 as soon as it was identified at visible wavelengths, several days before the peak of the eruption. He continued observing J1859+226 every one or two days for the next six weeks. The HET observations are a unique contribution to understanding how black holes attract and swallow matter.

The namesakes of the Hobby-Eberly Telescope are William P. Hobby, the former Lieutenant Governor of Texas, and Robert E. Eberly of Pennsylvania, an industrialist and philanthropist. The HET stands on Mount Fowlkes at McDonald Observatory in far West Texas, which has the darkest skies of any major observatory in the continental United States.

The Hobby-Eberly Telescope: A joint project of The University of Texas at Austin, The Pennsylvania State University (Penn State), Stanford University, Ludwig-Maximilians-Universität München, and Georg-August-Unversität Göttingen