Yale astronomers have discovered seven new dwarf galaxies, using a new design of telescope. They found the galaxies while studying a nearby spiral galaxy.
Although the discovery would have to be confirmed by other researchers, it is possible the astronomers from Yale may have recognized a previously-unknown class of astronomical objects.
The seven dwarf galaxies are extremely diffuse, looking more like clouds of thin nebulae than the dense families of stars that make up the Milky Way and Andromeda. The astronomers who discovered the galaxies believe the dim nature of the bodies is what prevented them from being discovered before now.
This new design of astronomical equipment uses a series of telephoto lenses. The "homemade" telescope consists of eight telephoto lenses, controlled as a single object, using a computer. Special coatings on each lens eliminate stray light reflecting inside the telescope. These features make the instrument ideal for spotting faint, diffuse galaxies like the septuplet recently discovered.
The Dragonfly Telephoto Array was designed by Pieter van Dokkum, head of the astronomy department of Yale in 2012. To create the instrument, he worked with Roberto Abraham of the University of Toronto. The name comes from the way the stacked lenses resemble the compound eyes of its namesake insect.
"These are the same kind of lenses that are used in sporting events like the World Cup. We decided to point them upward instead," van Dokkum said.
The telescope is housed at the New Mexico Skies observatory near Mayhill.
Discovery of the galaxies could assist astronomers, piecing together the mysteries of dark matter and evolution of galactic systems.
"We knew there was a whole set of science questions that could be answered if we could see diffuse objects in the sky. It's a new domain. We're exploring a region of parameter space that had not been explored before" van Dokkum stated in a university press release.
Further research will try to determine if the faint bodies seen near the M101 galaxy orbit that body, or simply lie in the same direction, as seen from Earth. Current astronomical theories suggest that such thin dwarf galaxies should occasionally form outside larger galaxies, like M101. If they are found to lie outside the gravitational influence of the galactic body, these dwarf galaxies could represent a type of object never before seen by astronomers.
"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," van Dokkum told reporters.
Discovery of the seven galaxies using the unique telescope was announced in The Astrophysical Journal Letters.
