In what has to be the largest cosmic collision of clever names and fairy tale references ever, Yale astronomers have discovered seven dwarf galaxies surrounding a pinwheel galaxy using a Frankenstein-like telescope they pieced together from eight lenses which they call the Dragonfly because it looks like an insect’s eye.
Pieter van Dokkum of Yale’s astronomy department designed the robotic Dragonfly Telephoto Array using eight telephoto lenses with special coatings that stop internal light from scattering. Sounds sophisticated but van Dokkum says otherwise.
These are the same kind of lenses that are used in sporting events like the World Cup. We decided to point them upward instead.
According to their recent report in the Astrophysical Journal Letters, the coatings allowed van Dokkum and University of Toronto astronomer Roberto Abraham to spot seven dim never-before-seen galaxies with very diffuse surface brightness surrounding the M101 spiral galaxy. M101 is about 21 million light years from Earth and it’s unclear using the Dragonfly if the seven dwarfs are orbiting it or just in the same area of Earth’s sky. Further investigation using the Hubble telescope should give an answer. Here’s van Dokkum’s prediction:
I’m confident that some of them will turn out to be a new class of objects. I’d be surprised if all seven of them are satellites of M101.
It’s expected that studying the seven dwarf galaxies will provide new insights into galaxy formation and dark matter. The Dragonfly Telephoto Array is also being used to search for space debris from galactic collisions.
As the Yale team works long hours mining for more data on the seven dwarf galaxies, all are sleepy but none are grumpy.