Astronomers say they have successfully used a "homemade" telescope created by stitching telephone lenses together to discover seven previously unseen dwarf galaxies.
The discovery of a possible new class of objects in deep space may provide important clues about dark matter or the evolution of galaxies, the astronomers from Yale University say.
The discovery was made using a robotic telescope consisting of eight telephoto lenses specially coated to suppress the internal scattering of light.
The astronomers said that allowed them to image the seven dwarf galaxies that had previously been overlooked due to their significantly diffuse nature.
"We got an exciting result in our first images," says Allison Merritt, first author of a published paper describing the find. "It was very exciting. It speaks to the quality of the telescope."
Yale's Dragonfly Telephoto Array is uniquely suited to detecting the new galaxies, which have very diffuse and low apparent brightness.
"These are the same kind of lenses that are used in sporting events like the World Cup," says Yale astronomy department chair Pieter van Dokkum. "We decided to point them upward instead."
Installed at a New Mexico observatory, the eight-lens telescope was dubbed Dragonfly for its resemblance to the compound eyes of insects.
The galaxies were discovered when the researchers turned the telescope toward a nearby spiral galaxy, M101. Further observations will be needed to determine if the dwarf galaxies are orbiting M101 or if they are instead either much closer or much farther away.
"We knew there was a whole set of science questions that could be answered if we could see diffuse objects in the sky," van Dokkum says. "It's a new domain. We're exploring a region of parameter space that had not been explored before."
Although the true nature of the dwarf galaxies has yet to be determined, they deserve close study because some current galaxy formation theories predict populations of such isolated, diffuse galaxies throughout the universe, Merrit says.
"It may be that these seven galaxies are the tip of the iceberg, and there are thousands of them in the sky that we haven't detected yet," she says.
The discovery is considered significant enough for the Yale team to have been granted time on the Hubble Space Telescope for additional investigation of the newly found galaxy septuplets.
"I'm confident that some of them will turn out to be a new class of objects," van Dokkum says. "I'd be surprised if all seven of them are satellites of M101."
