Construction of observatory for Giant Magellan Telescope will begin this year

Cornerstone of giant telescope to be installed in Chilean Andes will be laid in early November. Announcement was made at FAPESP Week Buenos Aires.

By Elton Alisson, in Buenos Aires

Agência FAPESP – In early November 2015, the international consortium of the Giant Magellan Telescope (GMT) project will start building the observatory and the mechanical structure for the mega-telescope, to be installed in the Chilean Andes.

The announcement was made during a round-table session on large-scale scientific collaborations held on April 8 as part of FAPESP Week Buenos Aires.

Hosted in Buenos Aires by FAPESP in partnership with Argentina’s National Scientific & Technological Research Council (CONICET), the event brought together researchers from São Paulo State and several higher education and research institutions in Argentina to discuss an increase in scientific collaboration between the two countries.

“Work began on the optical part of the telescope before construction of the observatory started,” said João Evangelista Steiner, a professor at the University of São Paulo’s Institute of Astronomy, Geophysics & Atmospheric Sciences (IAG-USP). “The first optical mirror, with a diameter of 8.4 m, is ready. Two others are being ground and polished, and casting of the glass for the fourth mirror is about to take place very soon,” Steiner told Agência FAPESP.

“Construction of the building and the entire mechanical structure for the telescope couldn’t begin until we had sufficient funding to guarantee construction of the telescope. In addition, we need all four mirrors up and running so that observation can start.”

According to Steiner, funding for the projected was completed by FAPESP when it joined the international consortium in late 2014.

FAPESP will invest US$40 million, equivalent to approximately 4% of the project’s estimated cost. This investment ensures that researchers from São Paulo State will have 4% of the GMT’s operating time for their own observations as well as giving Brazilian astronomers a seat on the consortium’s board.

Participation by researchers from São Paulo in the GMT will follow the same format as collaboration in the Gemini observatories, which began operating in 2000 with “twin” telescopes, one in the Chilean Andes and the other in Hawaii, and collaboration in the Southern Astrophysical Research (SOAR) telescope, which saw first light in 2004.

Brazil has a 6% share in observations via Gemini, whose telescopes are equipped with 8.1 m diameter mirrors, and a 30% share in SOAR, which has a 4.2 m mirror.

“The increase in the number of articles published by Brazilian astronomers in recent years is directly linked to our participation in Gemini and SOAR,” Steiner said during his presentation at the event.

“We had stagnated for almost a decade in terms of scientific publications and the number of professionals with master’s and doctoral degrees in the field. After Gemini and SOAR began operating, these two indicators rose at a brisk pace.”

GMT

The GMT will be installed at the Las Campanas Observatory in the Atacama Desert near the town of Vallenar in the Chilean Andes. This region is particularly well suited to astronomical observation because of its altitude. The site is more than 2,500 m above sea level and was also selected for its dry climate and access to the dark skies of the Southern Hemisphere.

The GMT will enable astronomers to investigate the formation of stars and galaxies shortly after the Big Bang, measure the mass of black holes, and map their immediate vicinity. It will assist in the discovery and characterization of planets orbiting around other suns, possibly leading to the detection of exoplanets similar to Earth, and can be used to study the nature of dark matter and dark energy.

Seven of the largest optical mirrors ever built will form a single telescope with an effective aperture of 25.4 m. Powerful lasers will be used to measure and correct the distortions caused by Earth’s atmosphere, allowing images of distant celestial objects to be produced with unprecedented clarity.

The photon collection area will be 100 times that of the Hubble Space Telescope. The infrared images produced by the GMT will be ten times sharper than Hubble’s, and it will have 30 times the resolving power of current telescopes, meaning that the amount of data it will make available will be that much greater.

Commissioning of the GMT is scheduled to begin in 2021.

“When construction of the observatory begins, a call for proposals will be issued for the fabrication of the telescope enclosure, a huge quasi-cylindrical structure that will require 4,000 metric tons of steel and must be very well designed,” Steiner said. “Brazilian companies are interested in building this structure.”

The Brazilian researchers will also participate in the development of some of the scientific instruments that will be used in the observatory.

“There are a number of technological packages that we can take on board and that involve technologies that are highly typical of the aerospace industry. We’re mapping the technological packages of interest and contacting potential bidders,” Steiner said.

In addition to the GMT, two other giant telescopes are being developed internationally: the European Extremely Large Telescope (E-ELT), coordinated by the European Southern Observatory (ESO), and the Thirty Meter Telescope (TMT), run by the California Institute of Technology and the University of California.

For more information about FAPESP Week Buenos Aires and to download presentations delivered there, please visit www.fapesp.br/week2015/buenosaires.