By J. Ferguson
Arizona Daily Wildcat
Wednesday, October 27, 2005
The most powerful telescope in the world achieved a milestone two weeks ago when it captured its first image of a nearby galaxy.
With more than 20 years and $120 million invested, these first light images from the Large Binocular Telescope, to which the UA is a principal partner, signaled a shift from construction to cutting-edge astronomical research.
These "first light" images mean they are the first astronomical pictures to be taken since the telescope's construction.
"It is wonderful to see the LBT returning its first astronomical result," said Peter Strittmatter, director of Steward Observatory and president of the LBT Corporation. "It has been quite a long haul."
Strittmatter called first light a momentous occasion for the international astronomical community, and the images exceeded the expectations of LBT astronomers.
Often, the first light images of a new telescope are unremarkable because various elements must be adjusted for optimum efficiency, said Richard Green, LBT director.
The images released yesterday are only from one primary mirror, as the second primary mirror is still being installed, Green said. The second mirror is expected to produce its first light image in the next few months, with the telescope in full operation by fall 2006, he said.
The pictures taken of the NGC891 galaxy will allow UA researchers and its partners to look deeper into the universe than ever before.
The telescope, perched atop Southern Arizona's Mount Graham, is expected to have 10 times the resolution of the Hubble Space Telescope. Astronomers at the LBT will use its unparalleled observational capability to view distant planets, the formation of galaxies and to detect dark matter, Green said.
The state-of-the-art camera on the telescope also helps astronomers increase the field of view, Green said.
The Large Binocular Camera, mounted on top of the primary mirror, can capture deep images of the universe over a large field of view, unlike most ground-based telescopes, which can only offer a narrow field of view, Green said.
The UA part of the LBT puzzle
Twenty years ago, the LBT was just a concept that was designed by UA astronomers Roger Angel and Nick Woolf. The pair was designing the next generation of telescopes based on current available technologies.
Woolf said after consulting peers in the field, the design for the LBT was narrowed down to putting two mirrors together.
The use two mirrors to form a single image in not unusual, as a similar setup is being used in the Keck telescope in Hawaii. The LBT mirrors are unique because the mirrors reside on a single mount of the telescope, not next to each other like the Keck telescope, Angel said.
Once the design was complete, the telescope planners encountered more problems in the early 1990s when a series of problems on Mount Graham threatened whether it would be constructed.
The endangerment of the red squirrel, the pure spruce and concerns from the San Carlos Apaches delayed the project. But after the UA reached agreements that limited the size and scope of the project, construction began in 1997.
The telescope was again threatened in the summer of 2004 when the Nuttall fire came within a quarter mile of the LBT facility. Fire wasn't the only danger to the telescope, Green said, recalling that a wave of heat damaged an Australian telescope several years earlier.
Extreme heat has the potential to melt aluminum and other telescope components, Green said.
The site Mount Graham was the best choice for the telescope's construction, Green said, because it was an area with low moisture and mainly clear skies. It was also the last place in the U.S. viable for observations, Woolf said.
The low amount of man-made light on the Mount Graham horizon ensures the location will be viable for years to come as agreements with local and county officials have been implemented, preventing future construction from minimizing ambient light, Green said.