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UM discovery DeeDee may be newest dwarf planet

Kim Kozlowski
The Detroit News

Look out, Pluto. A new celestial object discovered by University of Michigan astronomers could be the cool new dwarf planet.

Located more than 90 times farther from the sun than Earth, the object — named 2014 UZ224 — is poised to join five other dwarf planets in the solar system. UM researchers have nicknamed it “DeeDee,” short for distant dwarf.

DeeDee’s discovery perhaps sets the stage for UM researchers to find a new, theoretical planet outside the solar system known as Planet Nine.

UM physics and astronomy Professor David Gerdes, who led the discovery of 2014 UZ224 with a team of students, said the goal of the search was to find Planet Nine, which was theorized to exist in 2014 because of evidence of several objects with patterned, elliptical orbits, suggesting the pull of a massive planet.

Gerdes said the DeeDee find, the first made by UM, is intriguing because scientific discoveries aren’t made often, and this one is the second-most distant object in the solar system. They found it last summer with thousands of computers looking for patterns among thousands of images of the sky.

“We’re opening a new set of eyes to the solar system,” Gerdes said. “And the cat is going to drag out more stuff like this.”

Pluto is perhaps the most famous dwarf planet. It made headlines around the world when it was discovered as the ninth planet in 1930, then stirred an international outcry 10 years ago when it was reclassified as a dwarf planet because of astronomers’ new definition of a planet.

Mike Brown — a California Institute of Technology planetary astronomy professor often known as “the man who killed Pluto” — maintains a website with a chart showing 2014 UZ224 as “highly likely” to become a dwarf planet. Brown and his team in 2005 discovered dwarf planet Eris.

But even more than UM’s discovery, Brown said via email, is the process used by the researchers to discover this new object.

“What is even more exciting, the computer programs that they used could not just aid in the discovery, they could make the discovery,” Brown said of Plante Nine. “The current discovery, while not directly related to Planet Nine, really shows that these guys are on track to have a shot at finding the big one. And even if they don't, they will certainly find more objects that point the way.”

Gerdes, originally a particle physicist, used to hunt for new particles. But now he is looking for distant objects in space.

“Both involve looking for very small signals in very big complicated data sets,” Gerdes said.

DeeDee was discovered with the Dark Energy Survey, an international collaboration of scientists working to map and discover the cosmos. Its instrument, a Dark Energy Camera, is a very sensitive, 570 megapixel camera that is capturing images of the galaxies in Chile, helping scientists understand the acceleration of the expanding universe by surveying 1/8 of the sky over five years.

Gerdes, his students and collaborators at the University of Pennsylvania examined 16,000 images captured by the Dark Energy Camera to see what might be moving among the stationary stars and galaxies in the images. To help them, the team used thousands of computers at the Fermi National Accelerator Laboratory outside Chicago, along with UM computers, to process hundreds of terabytes of data.

“If it had been done on a single computer, it would have taken 300 years,” Gerdes said.

To be considered a dwarf planet, the object must orbit the sun, not be a satellite and not clear the neighborhood around its orbit. The main thing to satisfy the criteria is to determine that it’s large enough to be round, as opposed to potato-shaped, Gerdes said.

That’s why another telescope that is even more sensitive, ALMA — the largest astronomical project in existence with a revolutionary telescope — has since photographed the object to help measure its size.

It not clear yet how big the object is but researchers say its diameter could be anywhere from 350 to 1,200 kilometers. A more accurate measurement will be available in the next few weeks after scientists have finished analyzing the ALMA image.

“The most interesting thing about DeeDee is not that it’s unique,” Gerdes said. “It’s that there are probably dozens of other worlds like it out there, waiting to be found.”

Many have reported that UM has discovered a new dwarf planet. But the object has not been declared a dwarf plant, said Lars Lindber Christensen, spokesman for the European-based International Astronomical Union.

“The work classifying dwarf planets is done by members of the IAU's Committee on Small Body Nomenclature (CSBN) and the IAU Working Group for Planetary System Nomenclature (WGPSN),” Christensen wrote via email from Germany. “We cannot give a prediction of whether this object may become a dwarf planet or when it might happen.”

A dwarf planet designation is probably likely but as work continues, Planet Nine remains the big goal as Gerdes and his team continue to examine hundreds of other objects they found.

“Planet Nine is the really big prize out there,” Gerdes said.