New telescope opens in Chile with look at star cluster
UNIVERSITY OF ARIZONA NEWS RELEASE
Posted: September 27, 2000
First light image released from the Baade Magellan I telescope. It is an image of NGC 6809, a star cluster 20,000 light years away, taken with the CCD guide camera at one Nasmyth instrument port with a 20 second unguided exposure and no filter, on Sept. 15. Photo: University of Arizona.
The Magellan Project is a partnership between the Carnegie Institution of Washington, the University of Arizona, Harvard University, the Massachusetts of Technology, and the University of Michigan. These partners have been designing and constructing the unique Southern Hemisphere telescopes since 1993.
"First light" is achieved only after all of the optical elements of a telescope are placed in the mount and aligned. On September 15, two days after stormy weather, the slit of the dome atop Cerro Las Campanas was opened, and the giant 6.5-meter (22-foot diameter) mirror was uncovered and pointed towards NGC 6809, a star cluster 20,000 light years away. The stellar light streamed for the first time onto the primary mirror, then the secondary, then the tertiary, finally making its mark on the CCD (charge-coupled device) camera. Magellan Project Scientist Steve Shectman was at the controls, tweaking the focus and adjusting the thermal system, when the first image was recorded.
The small, round images of the stars indicated an extraordinarily fine optical system that could take advantage of the unusually good "seeing" at Las Campanas Observatory.
"The completion of the telescopes is a phenomenal collaborative achievement," notes Dr. Augustus Oemler, Jr., Director of Carnegie Observatories. "They will enable us to observe faint objects near the edge of the universe that are seen far back in time."
"The telescope will completely change the way we do science," commented John Mulchaey, an astronomer at Carnegie Observatories. "We can now do studies that we couldn't even dream of doing just a few years ago."
Each partner of the Magellan Project has its own scientific agenda for the new telescopes. The large apertures will facilitate observations of distant, high-redshift objects and the uniquely wide fields mean that entire clusters of galaxies can be observed at one time. Consortium astronomers hope to understand our origins by studying the chemical history of the first stars in our Galaxy, as well as the first galaxies to form near the edge of the universe. They will search for objects orbiting black holes, investigate fiery galaxy collisions, and map out the large-scale structure of the universe.
Since the time of Galileo, the need to peer deeper into the universe has driven astronomers to build ever larger and more capable telescopes. Most of these telescopes are situated in the Northern Hemisphere, but only from the Southern Hemisphere can we observe the center of our own Galaxy and our nearest neighboring galaxies, the Clouds of Magellan. The clear, dark skies of the Chilean Andes are unsurpassed anywhere on earth. The Magellan telescopes will comprise the majority of the access to the Southern sky for U.S. astronomers.
 The Magellan telescope. Photo: University of Arizona |
The Magellan mirrors are a radical departure from the conventional solid-glass mirrors used in the past. They are honeycombed on the inside, and made out of Pyrex glass that is melted, molded, and spun into shape in a specially designed rotating oven. The paraboloid mirrors were cast and polished by the University of Arizona Mirror Lab.
Matt Johns, Magellan Project Manager, and members of the Magellan team will commission the telescope over the next few months so that it will be ready for scientific observations in February 2001. The Magellan Project is named after Ferdinand Magellan, the Portuguese explorer who first circumnavigated the earth.
The 50-foot-high, 150-ton telescopes slew and point with the accuracy of a Swiss watch. In order to achieve the smooth, near-frictionless motion required for tracking astronomical objects, the telescopes float on a film of high pressure oil only two-ten-thousandths-of-an-inch thick. They are so well balanced that a tiny child pushing on the telescope could move all 150 tons.
"People don't think of Los Angeles as a location where scientific instruments of this magnitude are fabricated," according to David Chivens, one of the owners of L & F Industries, where the twin telescopes' alt-azimuth mounts were fabricated.
Science instrument commissioning will take a break in December when the dedication of the Magellan facility at Las Campanas Observatory is scheduled to take place
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