New Huntsman Telescope Turns its Eyes to the Sky

Australian scientists and astronomers will now have an extra set of eyes to look into the night sky, with the unveiling of a powerful new, multi-lensed instrument at the Siding Spring observatory in north-central NSW, near the town of Coonabarabran.   

The Huntsman Telescope is an optical wavelength instrument made up of an array of 10 Canon EF 400mm f/2.8 super-telephoto lenses that have now finished the commissioning phase and entered into science operations. 

Developed by Macquarie University, and supported by Canon Australia, the telescope will hunt for and study ultra-faint galaxies and astronomical objects in the southern hemisphere, with scientific objectives such as providing an understanding of galaxy formation and evolution; how galaxies form, how they grow, how they engage with structures that surround them, and what happens when galaxies collide. 

Additionally, the telescope is expected to set its gaze upon transient astronomical events - the unpredictable things that happen unexpectedly in space, like when a star suddenly explodes or when a gravitational wave merger happens in a certain region of the sky. Working in concert with other astronomical instruments, the Huntsman Telescope will be able to quickly turn and pivot its multi-eye configuration towards these regions, hopefully catching some of the light.

According to Principal Investigator of the Huntsman Telescope, Dr Lee Spitler, from Macquarie University’s School of Mathematical & Physical Sciences and Australian Astronomical Optics-Macquarie, the Huntsman Telescope’s work will be crucial to understanding what might happen should our Milky Way Galaxy have a head-on collision with its neighbour, the Andromeda Galaxy – an event theorised to occur in 4.5 billion years. 

“The Huntsman Telescope is pioneering the way in which we view our Southern skies by capturing images of the faintest galaxy structures that conventional telescopes simply couldn’t,” says Dr Spitler. “The ability to observe the remnants of galaxies colliding with each other and searching for the faintest and smallest galaxies in the Universe will help us understand the potential fate of the Milky Way in the far distant future.”

Each of the ten individual “eyes” of the Huntsman Telescope’s array are equipped with a single monolithic wide-field detector covering six square degrees. With multiple redundant lines of sight, Huntsman will use refracting lenses as opposed to reflecting mirrors, meaning there is no central obstruction that can cause light to scatter. This is important in achieving quality grade images of low surface brightness objects, like faint galaxies. 

The telescope will also take simultaneous images in multiple bands, giving it a good opportunity to spot a transient astronomical event - which can only last a mere few seconds or a couple of short weeks. It’s the only telescope of its kind in the southern hemisphere.

Additionally, each lens features an anti-reflection, second-generation Canon EF coated lens, designed to avoid any of the subtle structures that can be introduced with conventional mirror surfaces. This special feature will allow astronomers to study the faint, extended structures that are present around galaxies. 

The Huntsman Telescope project is a jointly-led project from Macquarie University School of Mathematical and Physical Sciences and the Australian Astronomical Optics-Macquarie, both within the Faculty of Science and Engineering at Macquarie University. Canon Australia are also a partner on the project - working side by side with the astronomers to achieve this goal. 

“For 80 years, Canon has been committed to developing precision optical technologies that exceed the needs of our customers, and we’re proud that our EF-lenses will play a role in helping Australian scientists tackle some of the most critical questions in astronomy today,” said Kotaro Fukushima, Managing Director, Canon Oceania. 

According to Sarah Caddy, PhD Candidate from the School of Mathematical and Physical Sciences at Macquarie University, The Huntsman Telescope was inspired by the Dragonfly Array program in the northern hemisphere, both sharing similar science goals to study the structure and evolution of galaxies, like the ultra diffuse and dwarf galaxies. But when it comes to Hunstman, the technology was pushed further.

The approach of combining individual EF 400mm f/2.8 L IS II super-telephoto lenses will enable the Huntsman telescope to scale with the needs of scientists in the future. Recent upgrades to the telescope are already set to further enhance Huntsman’s abilities in studying the Universe. 

“The Huntsman’s new suite of powerful computers enable each lens or ‘eye’ of the Huntsman to operate independently of each other. This will allow the telescope to autonomously detect ultra-fast transient events like stellar flares from distant stars or even more exotic phenomena like aiding the search for origin of fast radio bursts that continue to elude astronomers,” says Ms Caddy.

“After the success of Dragonfly in the northern hemisphere, it certainly makes sense to have a similar facility here in the Southern Hemisphere to access parts of the sky that Dragonfly can’t,” she said, highlighting the importance of having a telescope of this nature looking at southern skies. 

“Not only that, but Australia is home to many world-class radio telescope facilities. Combining data from radio surveys of the southern sky with Huntsman optical data will help us piece together a more complete view of how galaxies evolve.” 

“Even the geographical location of Australia is important for Huntsman’s transient science goals. Huntsman will contribute to the growing number of Australian rapid response facilities aiming to capture events like the optical counterparts to Fast Radio Burst and Gravitational Wave progenitors.”

The Huntsman Telescope is also planning on a number of key science targets, including observations of astrophysical objects, even before the Sun has set. 

“A future target that I am really excited to explore with Huntsman is the variable red supergiant star Betelgeuse. Specifically, taking images of Betelgeuse during the day! It does sound a bit crazy, but we are exploring the capabilities of Huntsman observing bright targets like stars during the day,” said Ms Caddy.

“There is a significant portion of the year when Betelgeuse is so close to the sun that we can’t observe it at night, and this leaves a big gap in the light curves that Astronomers use to monitor the star's brightness. After Betelgeuse’s odd behaviour in 2019 - 2020 when it dimmed significantly (and even caused speculation that it might explode in a supernova) I’m excited to contribute to efforts aimed at filling in those missing gaps in the light curve.”

Of the nine members of the Huntsman Telescope’s technical and science team, five are Macquarie University PhD students, who are benefiting from the unique opportunity to have hands-on training with such high-tech equipment. 

So what’s next for the team working with this brand new telescope? 

“What comes next for the team is to sit back, relax, and watch the data roll in!... Well, maybe not too much relaxing. While Huntsman is robotic, both the Huntsman Telescope and the team are still learning how to work together to achieve our science goals.” 

“We are so excited to see the project move from the commissioning phase into full-time science mode, and I can’t wait to see how this amazing new facility will help Astronomers explore our Universe in the years to come,” she concluded.