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The first of the giants

São Paulo researchers will have 4% of observation time on the GMT, the super ground telescope that will produce images 10 times sharper than those of the Hubble telescope

Illustration of what the GMT will look like: study of other worlds will be a priority

Giant Magellan Telescope – GMTO Corporation Illustration of what the GMT will look like: study of other worlds will be a priorityGiant Magellan Telescope – GMTO Corporation

Equipped with mirrors with a diameter of over 20 meters (m) and with a resolution 10–15 times greater than that of the Hubble Space Telescope—the most successful instrument for observing the Universe of the past 25 years—the land-based optical super telescopes should take astronomical and cosmological research to higher levels in the next decade. This new class of giant observers of the heavens will be able to generate unparalleled data on planets, stars and galaxies in the visible and infrared wavelengths. With them, astrophysicists hope, for example, to produce the first images of extrasolar planets similar to Earth and perhaps find irrefutable evidence of life on worlds around stars other than the Sun. The Giant Magellan Telescope (GMT) is expected to be the first super telescope to come on-line. It should begin to operate in 2021, even before being fully complete. The goal is for it to be totally operational, at 100% of its capacity, the following year. This, at least, is the plan for now.

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A $1 billion project undertaken by a consortium of seven US universities and institutions, two Australian centers for astrophysics studies and the South Korean Institute of Astronomy and Space Science, the GMT officially incorporated the research institutions in the state of São Paulo into its group of partners in December 2014. On that occasion, after submitting the proposal for entry into the GMT consortium to a review process lasting nearly three years, FAPESP approved the request and released the first of eight annual installments of $5 million to ensure that astrophysicists linked to São Paulo universities would have 4% of the observation time on the equipment and one representative on the GMT board of directors.The super telescope will be built at an altitude of 2,500 meters in the southern portion of Chile’s Atacama Desert, on a site belonging to the Las Campanas Observatory, where the Carnegie Institution for Science, one of the American partner institutions, has maintained telescope facilities since the early 1970s. “In the past, if we had not had access to the Gemini and SOAR telescopes, Brazilian astrophysics would have withered away,” states João Steiner of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences (IAG-USP), coordinator of the project that gave São Paulo institutions access to the super telescope. “By the end of the next decade, the same could happen if we had not signed an agreement like this one with the GMT.”

The São Paulo astronomy network
Since 2000, the research done at Pico dos Dias—the main Brazilian observatory, in Minas Gerais, which has three small telescopes, the largest with a 1.6 m diameter mirror—has been stagnating or falling off. At the same time, the scientific articles published by Brazilian astrophysicists based on Gemini and SOAR observations has grown 17% per year. Current production is about 40 papers annually. Astrophysicists hope that entry into the GMT consortium will represent new impetus for the field.

The headquarters of the GMT partnership will be at USP, which supported the agreement and represents most of the scientific production in astrophysics in the state, but research groups from other universities in the state of São Paulo may also submit proposals for using super telescope observation time. “FAPESP’s recent investments in projects like GMT, LLAMA and CTA have created a situation in which São Paulo has the potential to become an international astrophysics hub,” says Augusto Damineli, also at IAG-USP, another researcher directly involved in the negotiations that led to São Paulo becoming a partner in the super telescope consortium. “We want to set up a São Paulo astronomy network, increase scientific production and the number of graduate students, and invest in science communication.”

Artistic representation of an exoplanet similar to Earth

David A. Aguilar (CFA) Artistic representation of an exoplanet similar to EarthDavid A. Aguilar (CFA)

In addition to GMT, two other large projects are competing in the giant telescope race: the Thirty Meter Telescope (TMT), a $1.2 billion initiative paid for by an international consortium of research institutions in the United States, Canada, Japan, China and India that will be built at an altitude of more than 4,000 m at the Mauna Kea Observatories, in Hawaii, where more than a dozen telescopes are installed; and the European Extremely Large Telescope (E-ELT), a project valued at just over €1 billion sponsored by the member states of the European Southern Observatory (ESO), to be installed at an altitude of 3,000 m at the top of Cerro Amazones, in the Antofagasta region of the Chilean Atacama Desert.

The TMT and the E-ELT will have mirrors with diameters of 30 m and 39 m, respectively. They will therefore be larger than the GMT, whose seven 8.4 m mirrors will work together as if they were one 24.5 m mirror, with a diameter two and half times larger than the largest ground-based telescopes now operating, such as the two Keck telescopes in Hawaii. Brazil does not have access to the TMT, and the use of the E-ELT, the ESO’s more ambitious project, depends on the ratification of the federal government’s agreement with the European Observatory (see page 22).

In theory, the construction timelines favor the GMT, the smaller of the two super telescopes, compared to its larger competitors. The TMT is scheduled to begin operations in 2023 or the year after. The most optimistic date for the inauguration of the E-ELT is 2024. In this scenario, while its two competitors will still be warming up, the GMT would be able to sprint ahead for maybe two years if it begins operating in 2021. Its advocates believe that this advantage increases the possibility of ensuring the precedence of discoveries for which researchers have been waiting. “One of the GMT’s most exciting studies is on planets with a mass similar to that of Earth. It will be the first telescope capable of confirming the existence of these planets, measuring their atmosphere and, if there life on them, detecting it,” says astrophysicist Wendy Freedman of the University of Chicago, president of the GMT board of directors.

Currently, among the nearly 1,900 exoplanets confirmed since 1995, only one to two dozen extrasolar worlds really resemble Earth, based on the meager information available today. That is, few seem to be rocky planets located in what is called the habitable zone, with mild temperatures and ideal environmental conditions allowing for liquid water and promoting life. “We will also study the cosmic dawn of the Universe, the primordial moments when the first stars, galaxies, supernovas and black holes were forming,” says Freedman. “We will have the first telescope sensitive enough to witness this process, see details of these muted objects and measure their distances.”

The cornerstone of the GMT will be laid on November 11, 2015 in Chile. The event will mark the beginning of civil works for construction of the observatory that will house the super telescope. Work began on the optical part of the GMT years ago. Three of the seven 8.4 m mirrors have already been molded at the University of Arizona, one of the project’s partners. One of these mirrors has been polished, a fundamental step in the finishing process. This month, manufacture of the fourth mirror will begin.

The GMT will also have a fiber optics center and four observational instruments, basically different spectrographs, which are devices that separate light into different colors (or spectra), such as ultraviolet, infrared and the visible frequencies. One of the spectrographs, the GMTIFS, will also be responsible for corrections made via the adaptive optics technique, which reduces image distortion caused by air turbulence. “Brazilian industry is capable of manufacturing parts for these instruments,” says astrophysicist Cláudia Mendes de Oliveira of IAG-USP, who is contacting companies in São Paulo interested in providing services and parts for the GMT and other astrophysics projects.

Project
Exploring the Universe, from the formation of galaxies to Earth-like planets, with the Giant Magellan Telescope (No. 2011/51680-6); Grant Mechanism: Special projects; Principal investigator: João Steiner (USP); Investment: R$17,860,000.00 and $40,000,000.00 (FAPESP).

018-025_CAPA Astrofisica_231-02

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