Dragonfly is an innovative, multi-lens array designed for ultra-low surface brightness astronomy at visible wavelengths. Commissioned in 2013 with only three lenses, the array is growing in size and proving capable of detecting extremely faint, complex structure around galaxies.
According to Cold Dark Matter (CDM) cosmology, structure in the Universe grows from the “bottom up”, with small galaxies merging to form larger ones. Evidence of such mergers can be seen in faint streams and filaments visible around the Milky Way Galaxy and the nearby M31 galaxy.
But the CDM model predicts that we should see more of this structure than is currently observed. However, images obtained using even the largest, most advanced telescopes today contain scattered light that may be hiding this faint structure. Dragonfly is designed to reveal the faint structure by greatly reducing scattered light and internal reflections within its optics. It achieves this using commercially-available Canon 400mm lenses, with unprecedented nano-fabricated coatings with sub-wavelength structure on optical glasses.
Also, Dragonfly images a galaxy through multiple lenses simultaneously—akin to a dragonfly’s compound eye—enabling further removal of unwanted light. The result is an image in which extremely faint galaxy structure is visible.
During 2025-2026, The Dragonfly Telephoto Array has been undergoing a spectacular metamorphosis!
In essence, Dragonfly is evolving into the Modular Optical Telephoto Hyperspectral Robotic Array (MOTHRA), with 1140 telephoto lenses spread over 30 large fork mounts at the Obstech observatory in Chile. The upgraded array will be equipped with ultra narrow-band tilted interference filters, a technology pioneered by the Dragonfly Spectral Line Mapper. Upon completion, MOTHRA will be the equivalent of a 4.8m aperture f/0.08 refractor with an R=800 integral field spectrometer and a 6+ square degree field of view.
MOTHRA’s science objective is to directly image the circumgalactic medium (the repository of most of the Universe’s baryons) and the brighter pockets of the Cosmic Web (which is hypothesized to connect galaxies to one another, and is thought to be the largest collapsed structure in the Universe). The original 48-lens broad-band Dragonfly imaging array will remain at New Mexico Skies, operating as a polarimetric imager.
MOTHRA will be owned and operated by Dragonfly FRO LLC, a Focused Research Organization*. More info about MOTHRA will be coming soon!
For more information about Dragonfly and MOTHRA please visit their new website.
The co-principal-investigators for Dragonfly are U of T’s Professor Roberto Abraham and Yale University’s Professor Pieter van Dokkum.
Articles about Dragonfly
New image reveals how dying stars return the ingredients of life to space
Revealing a Hidden Universe: First-of-its-kind telescope MOTHRA unveiled