Our Solar System is much more crowded than previously believed. The analysis of data from the DES (Dark Energy Survey) has revealed over 300 trans-Neptunian objects (TNO), minor planets in the far reaches of the solar system, including over 100 new ones.
Published in The Astrophysical Journal Supplement Series, the study also describes a new approach to finding similar types of objects and could aid future searches for the hypothetical Planet Nine and other undiscovered planets.
DES, which completed six years of data collection in January, aims to help experts understand the nature of dark energy by collecting high-precision images of the southern sky.
While DES was not specifically designed with searching for minor planets, its depth of coverage made it particularly adept at finding new objects beyond Neptune.
“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,” explained Bernstein.
As DES was designed to study galaxies and supernovae, the researchers had to develop a new way to track motion. Dedicated TNO surveys take measurements every one to two hours, allowing researchers to more easily track movements of cosmic objects.
“Dedicated TNO surveys have a way of seeing the object move, and it’s easy to track them down,” revealed Bernardinelli.
“One of the key things we did in this paper was to figure out a way to recover those movements.”
The first four years worth of data gave experts a dataset comprised of 7 billion dots, which are all the possible objects that were picked up by the software, and were above the image’s background levels.
Scientists then proceeded to remove the objects that were present on multiple observational nights—stars, galaxies, and supernova. This allowed them to create a “transient” list composed of around 22 million objects. They then proceeded in connecting the dots, “looking for nearby pairs or triplets of detected objects to help determine where the object would appear on subsequent nights.”
The researchers worked their way down, eliminating candidates. From a list composed of 7 billion dots, they worked their way until they had around 400 candidates that were observed over a period of six nights. Scientists then worke4d in verifying their results.
“We have this list of candidates, and then we have to make sure that our candidates are actually real things,” Bernardinelli explained.
The process is tedious. To filter their list of actual TNO candidates, the researchers went back to the original dataset to see if they could find more images of the objects in question.
“Say we found something on six different nights,” Bernstein explained. “For TNOs that are there, we actually pointed at them for 25 different nights. That means there are images where that object should be, but it didn’t make it through the first step of being called a dot.”
Bernardinelli worked out a way to stack various images in order to create a much sharper view, a process that helped confirm whether the objects that were detected were actually Trans-Neptunian objects.
After months of work, the scientists finally confirmed the discovery of 316 TNOs, including 245 discoveries made by DES and 139 new objects that were not previously published.
The updated TNO catalog will probably prove to be an extremely useful tool in studying the outermost reaches of the solar system and look for new Minor planets. Furthermore, the study of TNOs might also help scientists in their quest to find the whereabouts of Planet Nine, a theorized Neptune-sized world that orbits our sun somewhere beyond the orbit of Pluto.