Astronomers got a lot more information about one of the farthest objects in our Solar system – the planetary body 2014 UZ224, informally known as DeeDee.
DeeDee is at three times the current distance of Pluto from the Sun, which makes it the second farthest trans-Neptunian object, second only to the dwarf planet Eris. Astronomers believe that there are tens of thousands of such icy bodies like DeeDee, beyond the orbit of Neptune.
The new data from the Atacama Large Millimeter/submillimeter Array (ALMA), has the first measurement of the ice body – at 635 kilometers across it is large enough to achieve spherical shape, a needed criteria for it to have the designation of dwarf planet.
“Far beyond Pluto is a region surprisingly rich with planetary bodies. Some are quite small but others have sizes to rival Pluto, and could possibly be much larger,” said David Gerdes, scientist from the University of Michigan and founder of DeeDee.
“Because these objects are so distant and dim, it’s incredibly difficult to even detect them, let alone study them in any detail. ALMA, however, has unique capabilities that enabled us to learn exciting details about these distant worlds.”
DeeDee at this point of time is at a distance 92 larger than that of Earth from the Sun, and has a orbit of 1100 years. The light from it takes a whole 13 hours to reach our planet.
Gerdes announced the discovery of DeeDee in late 2016. He and his team found it using the 4 meter Blanco telescope in Chile, as part of the ongoing observations of the Dark Energy Survey, which tries to understand this “invisible” force in our universe.
The massive amount of astronomical images from the Survey gave the opportunity to search for distant solar system objects. While most were just background stars and galaxies, some of them were moving very slowly across the sky, a sign of a TNO (trans-Neptunian object)
An object was found in 12 different images and astronomers dubbed it Distant Dwarf or DeeDee.
However the data only allowed scientists to find it’s orbit and distance. There was a possibility of it being a small object reflective enough to be seen from Earth or a very large body that reflected a infinitesimally portion of it.
Using the ALMA, they were able to find it’s heat signature and it’s size. They calculated that is was freezingly cold- at 30 Kelvins it was just above the absolute zero.
By detecting the heat signature, they used to measure it’s brightness in the millimeter wavelength light.They found that it only reflected about 13 percent of the sunlight that reached it.
With these new observations and the previous data, astronomers were able to calculate the dwarf planet size.
“ALMA picked it up fairly easily,” said Gerdes. “We were then able to resolve the ambiguity we had with the optical data alone.”
Objects in our solar system
DeeDee is a cosmic leftover from the birth of our Solar system and may reveal important details about the formation of planets.
The discovery gives hope that astronomers can use the same techniques to find the elusive “Planet Nine” which may reside far beyond the orbits of both DeeDee and Eris.
“There are still new worlds to discover in our own cosmic backyard,” concludes Gerdes. “The solar system is a rich and complicated place.”