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Queue Scheduled Observing
The HET operates a queue scheduled observing program. Under this system, operation of the telescope, and the aquisition
of targets on the nightly observing list is the primary responsibility of the Resident Astronomer, who has flexibility to
alter the night's program. This mode of operations
is particularly well suited to the HET because it makes efficient use of observing time, and partially
compensates the telescope's access limitations to the visible night sky. The program makes the HET well suited to follow up
spectroscopic observations, and the consistent revisiting of objects over time.
Queue scheduled observing also has benefits that extend beyond supplementing the unique design of the HET.
The program encourages the study of
stellar events of limited duration, such as gamma ray bursts that have been spotted by chance at other ground or space
based observatories. And observers can also benefit, as significant investments of time and money are frequently lost in
most observing programs, simply because hard won telescope time happened to coincide with bad weather.
Amazing Truss
Many systems of the HET are remarkable for their precision and creatively engineered design. The
truss supporting the primary mirror array fits this category.
The truss was made by MERO Industries, in Wuerzburg, Germany at extremely low cost. The steel balls shown above were
robotically milled into truss nodes, like the example at left, part of MERO's patented connection technique.
The structure is made
from 383 nodes and 1,747 struts. Few of the parts are interchangable. The struts were manufactured to a precision of 0.0004
inches—about one-tenth the thickness of a human hair. Before shipping to Texas, the truss was test
assembled. Each node in the top surface of the truss was accurate to its theoretical position to better than 0.08 inches.
At McDonald Observatory, the pieces arrived in a single truckload and were assembled in six weeks by a MERO crew.
Under the dome of the HET, and the 27,000 pound weight of the primary mirror, the truss is
deflected just 2.5 millimeters.
Images and Amazing Truss content courtesy of The West Texas Time
Machine: Creating the Hobby-Eberly Telescope, Little Hands of Concrete Productions, 1998.
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