Giant Magellan Telescope

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Giant Magellan Telescope
Giant Magellan Telescope - artist's concept.jpg
Artwork of Giant Magellan Telescope
OrganizationGMT Consortium
LocationLas Campanas Observatory, Chile
Coordinates29°01.7′S 70°41.15′W / 29.0283°S 70.68583°W / -29.0283; -70.68583Coordinates: 29°01.7′S 70°41.15′W / 29.0283°S 70.68583°W / -29.0283; -70.68583
Altitude2,516 m[1][2]
Wavelength320–25000 nm[3]
BuiltAwaiting money
Telescope style Gregorian
Diameter25.448 m[4]
Angular resolution 0.21–0.3″ at 500 nm[3]
Collecting area368 m²[4]
Focal length18.000 m (M1)
202.745 m (M1+M2)[4]
Las Campanas Observatory, the site for the Giant Magellan Telescope

The Giant Magellan Telescope (GMT) will be the world's largest telescope when it is completed in 2025. Instead of one large mirror, the GMT will have seven separate mirrors working together. This will mean its collecting area is bigger than the actual mirror surfaces.[5] It will be made of seven 8.4 m (27.6 ft) diameter mirror parts.[6] It will have a the resolving power of a 24.5 m (80.4 ft) mirror. Its collecting area will be the same as a 21.4 m (70.2 ft) mirror. The telescope will have over four times the ability to gather light than existing telescopes. It will produce images up to ten times clearer than the Hubble Space Telescope.[7] It will cost $700 million.[8]

Planned site[change | change source]

The location of the telescope is the Las Campanas Observatory,[7] which is also the site of the Magellan Telescopes, some 115 km (71 mi) northeast of La Serena, Chile. This area has clear weather for most of the year.[9] The night sky in most of the surrounding Atacama Desert region is free from atmospheric pollution. With few cities nearby this is probably one of the places least affected by light pollution. All of this makes the area one of the best spots on Earth for long-term astronomical observation.

Design details[change | change source]

The telescope is unique because it will use seven mirror sections, each 8.4 m (27.6 ft) in diameter. These segments will then be arranged to form a single optical surface. This is difficult as the surface of the outer six mirror segments is not radially symmetrical (that is, they are off-axis). This requires a small change in the way mirrors are usually polished. All seven mirrors will be arranged so that the reflecting surface of each of them is on a common axis. One mirror will be in the center and the other six arranged symmetrically around the center. A focal plane will be on-axis with the entire assembly. The plan is to build seven identical off-axis mirrors. The spare mirror has been made to replace a mirror when it needs recoating, a 1–2 week (per segment) process required every 1–2 years.[10]

The Steward Observatory, at the University of Arizona, is making the mirrors in a laboratory beneath the university's football stadium. It is using a rotating furnace to make the mirror. The casting of the first mirror was completed on November 3, 2005. But the time-consuming shaping and polishing will be completed in the autumn of 2011.

The telescope will make use of adaptive optics.[11]

Member organizations[change | change source]

The following is a list of the group which is developing the telescope.[12]

George P. Mitchell, founder of Mitchell Energy & Development Corp., and The Cynthia and George Mitchell Foundation are giving $25 million to help pay for the telescope.[8]

Related pages[change | change source]

References[change | change source]

  1. José Terán U.; Daniel H. Neff; Matt Johns (2006-05-29). "Conceptual design study of the GMT enclosure" (PDF). Orlando, FL: SPIE. p. 2. Retrieved 2008-03-31.
  2. Joanna Thomas-Osip (2007-03-20). "Syposium on Seeing". Kona, HI: AAS. p. 3. Retrieved 2008-03-31.
  3. 3.0 3.1 "Giant Magellan Telescope Science Requirements" (PDF). GMT Consortium. Retrieved 2008-03-31.
  4. 4.0 4.1 4.2 "Chapter 6: Optics" (PDF). GMT Conceptual Design Report. GMT Consortium. p. 6–3. Retrieved 2008-04-02.
  5. Maggie McKee (2007-10-04). "Giant telescope in race to become world's largest". New Scientist. Retrieved 2007-10-07.
  6. "Giant Magellan Telescope Partner Institutions". GMT Consortium. Retrieved 2007-04-03.
  7. 7.0 7.1 "Giant Magellan telescope site selected". Carnegie Institution. Retrieved 2007-10-05.
  8. 8.0 8.1 "George Mitchell Commits $25 Million to Giant Magellan Telescope". Giant Magellan Telescope Organization. Retrieved 2011-09-07.
  9. Robinson, Travis (2007-04-03). "Eye on the sky". The Battalion. Retrieved 2007-04-03.
  10. "Telescope Structure". GMT Conceptual Design Report. February 2006. Retrieved 2007-10-07. Section 7.4.5, page 7-17.
  11. "Overview". Giant Magellan Telescope Organization. Retrieved 2011-09-07.
  12. "Giant Magellan Telescope Partner Institutions". GMTO. Retrieved 2009-02-11.

Other websites[change | change source]