A delegation from the Hobby-Eberly Telescope Project is meeting with astronomers, engineers, and officials in South Africa this week to discuss the possibility of collaboration on construction of a large astronomical telescope. The telescope would be patterned after the Hobby-Eberly Telescope (HET) currently nearing completion at McDonald Observatory in the Davis Mountains of remote west Texas, USA.
The telescope features the largest primary mirror in the world, 11 meters in diameter, and is made up of 91 hexagonal mirror segments, each 1 meter in size. In contrast to most telescopes, which track astronomical objects by moving the entire apparatus, the HET tracks by moving only the instrument package above the primary mirror to follow the moving, reflected, and focused image. This reduces the amount of telescope mass to be moved under precise control by more than 10 times.
While the HET cannot observe the entire sky, it can see over 70 percent of it, track for up to 3 hours, and feed the captured light to instruments via an optical fiber, permitting very large and sensitive instruments to be housed in a room beneath the telescope. The HET is being constructed for about 15% of the cost of telescopes of similar size currently in operation or under construction at sites in Hawaii and Chile.
It is primarily because of the large mirror at a relatively low cost that South African astronomers are interested in talking to the university partners of the HET, which include The University of Texas at Austin, The Pennsylvania State University, Stanford University, and the Universities of Munich and Goettingen in Germany. Also under discussion are plans for time sharing between the two telescopes and scientific collaboration between South African astronomers and those of the HET partnership.
The telescope could be constructed in five years, using the majority of plans and designs already developed for the HET. Under consideration would be the South African Astronomical Observatory site, near Sutherland. Sharing of software, electronic designs, and scientific instruments could provide substantial cost savings in operation as well as construction.
"The HET astronomers are very excited by the possibility of a South African twin," said Dr. Frank N. Bash, the Director of McDonald Observatory and representative of the HET Board. Other American visitors include the HET Project Scientist, Dr. Lawrence W. Ramsey of Pennsylvania State University, also one of the co-inventors of the HET concept; and Mr. Thomas A. Sebring, the HET Project Manager. "We have thus far developed the HET within the established budget and schedule by application of good management practices and through development of unique and elegant engineering designs," said Sebring.
At the University of Texas: Thomas A. Sebring, 512-475-6765
At Penn State: Barbara K. Kennedy, 814-863-4682
At South African Astronomical Observatory: Case Rijsdijk, 27-21-470025