Astronomers have discovered 139 new “minor planets” in our solar system, beyond the orbit of Neptune. These small objects could provide clues as to whether the mysterious Planet Nine, a hypothesized planet orbiting our sun which has not been directly observed, does really exist.
The minor planets were discovered using data from the Dark Energy Survey, a six-year project mainly focused on understanding dark energy. But the data collected is also useful for finding new bodies in our solar system, particularly trans-Neptunian objects or TNOs, because the survey covers a wide region of the sky in great detail.
“The number of TNOs you can find depends on how much of the sky you look at and what’s the faintest thing you can find,” Pedro Bernardinelli, graduate student at the University of Pennsylvania and leader of the research, said in a statement.
There was a challenge in using the data this way, however, as the researchers had to come up with a new way to track movement.
“Dedicated TNO surveys have a way of seeing the object move, and it’s easy to track them down. One of the key things we did in this paper was figure out a way to recover those movements.”
With the new method in place and an enormous dataset to explore, the researchers were able to identify 400 candidate objects which were seen regularly in our sky. Then they looked for objects which appeared consistently and whittled the list down to 316 identified TNOs. Of these, 139 had not been discovered before.
As for Planet Nine, much of the evidence in favor of its existence comes from observing the movements of TNOs. Some TNOs have been seen to cluster in strange ways which could suggest the presence of an unseen but massive body like a planet. The addition of this new set of data gives more chances for astronomers to observe this phenomenon.
“There are lots of ideas about giant planets that used to be in the solar system and aren’t there anymore, or planets that are far away and massive but too faint for us to have noticed yet,” said co-author Professor Gary Bernstein. “Making the catalog is the fun discovery part. Then when you create this resource; you can compare what you did find to what somebody’s theory said you should find.”
The results are published in The Astronomical Journal Supplement Series.
