The Dragonfly Telephoto Array is a telescope array equipped with multiple Canon large-aperture super-telephoto single focal length lenses – specifically, the Canon EF 400mm f2.8L IS II USM lens. The telescope was designed in 2013 by Project Dragonfly, an international research team from Yale University and the University of Toronto. The Dragonfly Telephoto Array is capable of capturing images of galaxies that are so faint and large that they had escaped detection by even the largest conventional telescopes. Its mission is to study the low surface brightness universe to elucidate the nature of dark matter and to utilise the concept of distributed telescopes.
In support of this research, Canon provided technical assistance by supplying 40 Canon EF 400mm f2.8L IS II USM lenses in 2015, expanding the array to 48 lenses with 24 telescopes bundled on two separate mounts. Since then, the research team has produced significant results in extragalactic astronomy, including discovering the ultra-diffuse galaxy Dragonfly 44 in 2016 and the identification of a galaxy that lacks dark matter, NGC 1052-DF2, in 2018.
This time, Canon will provide technical assistance by supplying 120 Canon EF 400mm f2.8L IS II USM lenses to the research team, further expanding the telescope array. With a total of 168 lenses, the telescope array has a light-gathering capability equivalent to that of a refracting telescope of 1.8 metres in diameter, with a focal length of only 40cm, and is expected to open new windows on the universe.
Canon is committed to contributing to the development of science and technology by leveraging the technological strengths it has cultivated as a leading imaging company.
Professor Pieter van Dokkum of Yale University comments
The Dragonfly Telephoto Array is the pre-eminent survey telescope for finding faint, diffuse objects in the night sky. It has enabled us to discover ultra-diffuse galaxies and other low-surface brightness phenomena—rendering images that deepen our understanding of how galaxies are formed and providing key insights into the nature of dark matter. The initial array was equipped with 48 Canon EF 400mm telephoto lenses featuring anti-reflection coatings that mitigate the effects of light scattering, overcoming the limitations of conventional telescopes in detecting faint structures. The lenses are coupled to monolithic wide-field detectors that permit excellent error control. With the addition of 120 of these lenses, in a newly developed configuration allowing extremely narrow filters to be used, Dragonfly will be the most powerful wide-field spectroscopic line mapping machine in existence. A major goal of the next iteration of the Dragonfly array is to detect and study the faint gas thought to exist around and between galaxies. By opening this new window on the cosmos, Dragonfly will tackle some of the most critical questions in astrophysics today.
For more information on how this project has developed, visit EOS magazine.