Beyond Neptune’s orbit there are countless ice rocks known as trans-Neptunian objects (OTN). One of the largest, Pluto, has been classified as a dwarf planet. The region also provides us with kites like the famous Halley. But most OTNs are small and receive little sunlight, making them weak and difficult to detect.
Now usingclever techniques for sifting through the data files of theHubble Space TelescopeNASA, a team of astronomers just added14 new OTNs to the catalog. And what is more interesting, his method promises to discover hundreds more. “The interest of trans-Neptunian objects is that they are building blocks left over from the formation of the Solar System,” says César Fuentes, a researcher at Northern Arizona University and lead author of the study.
As the OTNs travel slowly in orbit around the Sun, they move against the starry background, and appear as streaks of light in photographs taken during long exposure times. The team developed software to analyze hundreds of Hubble images to hunt down these lines. After detecting some promising candidates, the images were scrutinized to confirm or refute each discovery.
Most OTNs are near the ecliptic – a line in the sky that marks the plane of the Solar System. Therefore, the team searched within 5 degrees of the ecliptic to increase their chances of success. Have been found14 objects, including a binary (two OTNs orbiting next to each other like a miniature Pluto-Charon system). They are all very weak,more than 100 million times more than objects visible to the naked eye, and it is estimated that they are 40 to 100 kilometers wide.
This initial study, which will be published in the journalThe Astrophysical Journal, has surveyed only a third of a square degree in the sky, which means there is a lot of area to explore. Hundreds of additional OTNs may lurk in the Hubble archives at higher latitudes on the ecliptic. Fuentes and his colleagues intend to continue the search.
