The Giant Magellan Telescope (GMT) is a next generation optical/infra-red telescope, currently under construction at the Las Campanas Observatory in Chile. When completed in the early-2030s, the GMT will be 25.4 metres in diameter and will boast over six times the collecting area of the largest telescopes currently in existence.

Giant Magellan Telescope
A render of the future GMT at night. Credit: GMTO Corporation/M3 Engineering.
Giant Magellan Telescope
A render of the future GMT at night. Credit: GMTO Corporation/Mason Media Inc.
Giant Magellan Telescope Mirrors
With of seven of the world’s largest mirrors ever constructed, the future GMT will provide ten times better resolution than the Hubble Space Telescope. Image Credit: GMTO Corporation/M3 Engineering.

The telescope is currently being developed by GMTO on behalf of a consortium of institutions in the USA, Brazil, Korea, Israel, Taiwan and Australia. Australia holds a provisional 10% share in GMT through ANU and AAL.

Excavations for the foundations of the telescope’s pier and enclosure were completed in March 2019, and casting of the seven 8.4-metre primary mirrors is now complete. These primary mirrors and the overall design of the telescope, which will have an effective 25-metre diameter, will create a light-collection area six times greater than the largest telescope currently in existence and allow us to the see the Universe at a resolution 10 times sharper than the Hubble Space Telescope (HST). The combination of this light-gathering power and exquisite angular resolution will allow astrophysicists to gain incredible new insights into exoplanets orbiting nearby stars. Giant black holes in distant galaxies and the first stars formed in the early Universe just after the Big Bang will also be within reach of the GMT’s highly sensitive observing instruments, three of which are being designed here in Australia.

Local contributions to the future GMT include the Laser Tomography Adaptive Optics (LTAO) subsystem, being designed by ANU, which will correct for the blurring caused by Earth’s atmosphere and will allow the GMT to produce images that are sharper than those obtained by either the HST or the James Webb Space Telescope. The GMT Integral-Field Spectrograph (GMTIFS), also being designed by ANU, will have the ability to take detailed images of the sky and obtain spectra from across a continuous region of the field of view. Additionally, a team at Macquarie University are designing MANIFEST, a multi-object fibre positioner system that will enhance two of the GMT’s other spectrographs by increasing the field-of-view, the spectral resolution, and the number of objects that can be observed simultaneously.

The GMT is one of five research infrastructure priorities in the Decadal Plan for Australian Astronomy (2016-2025), namely a “partnership equating to 10% of a 30-metre class optical/infrared extremely large telescope (ELT), such as the Giant Magellan Telescope.”