A new technique could help astronomers to find new minor planets

Researchers from the University of Pennsylvania have discovered more than 300 trans-Neptunian (TNOs) using data from the Dark Energy Survey (DES). TNOs are minor planets that are in the far reaches of the solar system. Among those discovered by the researchers are more than 100 that are newly discovered.

The team has a new approach to finding TNOs and similar objects that they believe could aid in future searches for the hypothetical Planet Nine that many scientists believe exists in our solar system. DES has now completed six years of data collection, and its goal is to understand the nature of dark energy while collecting high-precision images of the southern sky.

DES wasn't explicitly designed to find TNOs, but the coverage its observations offer made it adept at finding objects beyond Neptune. DES was designed to study galaxies and supernovas, and that design meant that the researchers had to develop a new way to track movement. Surveys specifically for TNOs take measurements of often as every one or two hours.

That allows the scientists to see movement making it easy to track the objects down. Using the first four years of DES data, the team started with a dataset of 7 billion dots. Each dot was a possible object detected by software that was above the image background levels. All objects that were present on multiple nights were removed.

Those objects included stars, galaxies, and supernova. What was left was transient objects, and there were 22 million of them. The team then looked for nearby pairs of triplets of detected objects to determine where it would appear on subsequent nights. Eventually, the list was down to 400 candidates watched over at least six nights. Images were stacked to create a sharper view to help confirm if they were real TNOs or not. At the end of the study, the team had found 319 TNOs, including 245 discoveries made by DES and 139 new objects not previously published.