Bug’s eye view of the universe
University of Toronto cosmologist co-created a multi-lens telescope that can find the faint halo, the remains of a star, surrounding each galaxy
Cosmologist Roberto Abraham has his sights set on galaxies far, far away.
The University of Toronto astrophysicist is the cocreator of Dragonfly, a small, multi-lens array capable of detecting the most faint and hidden realms of outer space.
The array, composed of 10 commercial Canon 400mm f2.8 telephoto lenses, each with a price tag of $12,000, was inspired by the design of an insect’s wings.
The Star spoke with Abraham to learn more about Dragonfly and the role it will play in what he calls “the golden age” of intergalactic discovery.
This interview has been condensed and edited.
I have to get this out of the way: How did you come up with the idea of strapping a bunch of expensive camera lenses together?
Around three years ago, my colleague (Yale University’s Pieter van Dokkum) and I went out for a beer. We both asked if it was possible to still have some fun with crazy ideas and astronomy without needing $100 million and hundreds of people to build a telescope.
Following that beer, Dragonfly emerged.
Speaking of which, it does look like a bug’s compound eye.
Well, one of my colleague’s hobbies is taking pictures of insects. His favourite? The dragonfly.
What pictures are you taking exactly?
Akey idea behind galaxy formation is that big galaxies are built when smaller galaxies crash into each other.
According to this theory, there should be a faint halo, the remains of a shredded star, surrounding each galaxy.
You cannot find this faint structure in the sky with a conventional telescope. The mirrors inside can scatter light, which makes it more difficult to see.
Are all the lens connected to one another?
Each lens is totally independent, but they are bolted together in order to point at the same spot in the sky from a desert in New Mexico.
At the back of each lens, there is a miniature computer that makes sure all of the 10 pictures are taken at the exact same time.
Why New Mexico?
It is way less cloudy there compared to Toronto. With a telescope, you want the area it is in to be pretty dark. In New Mexico, Dragonfly is in the middle of nowhere and not nearly as close to a city that lights up at night.
The environment also means less goop can get on the lens, but they still require cleaning.
With a giant lens cloth, I bet?
There is a special technique we use to clean the lens, using a solution that we call carbon dioxide snow. It is the same safe cleaning method used on bigger telescope mirrors.
Were all the lenses purchased at once or did you assemble it one piece at a time?
For the first lens, we went 50/50 on it each and travelled to an observatory in Montreal. It was spectacular, but we needed more lenses.
Any discount for buying bulk?
The Canon Corporation was helpful, that’s all I can really say.
How big are the photos?
is roughly16 megabytes. After they are shot, we digitally stack them up on top of each other.
Are they JPEGs?
We use astronomical cameras so the closest DSLR-equivalent format would be RAW. The sensors that process these photos are actually piggy-backing on the same tech used in cellphone camera sensors.
What do you see for Dragonfly’s future?
We’ve recently secured a bunch of money to upgrade from10 lenses up to 50, making Dragonfly the largest all-- refracting telescope in the world. It almost grows organically. Every time we have an extra $12,000 we can bolt on another lens. There’s going to be nothing like it out there, and it’s going to let us do some amazing science.
Such as?
We are just scratching the surface of what we know about the universe, but so far, we have already found 50 new galaxies. This thing has proven itself to be incredibly productive.
But it also shows that you can still have a big impact in astronomy these days with a little imagination. That’s kind of magical.