A team of researchers, using data from the W. M. Keck Observatory on Maunakea and NASA’s Hubble Space Telescope, has identified what is likely a rare three-body system in the Kuiper Belt. If confirmed, the 148780 Altjira system could change how scientists understand the formation of objects in a distant region of the solar system.
“This discovery is scientifically fascinating because we don’t know how to distinguish between different models of how this part of the solar system formed, and the existence of triple systems helps rule one model out,” said John O’Meara, chief scientist and deputy director at Keck Observatory. “With adaptive optics (a system specifically designed to reduce atmospheric blurring), we can be as sharp an eye on the sky as a space telescope, complimenting Hubble’s strengths.”
Altjira, located 3.7 billion miles from Earth, was previously thought to be a binary system. However, after analyzing 17 years of observational data, researchers discovered that one of the two visible objects is actually two closely bound bodies. If verified, this would be only the second known triple system in the Kuiper Belt.
The study, led by Brigham Young University, was recently published in The Planetary Science Journal.
“The universe is filled with a range of three-body systems, including the Alpha Centauri star system, and we’re finding that the Kuiper Belt may be no exception,” said lead author Maia Nelsen from Brigham Young University.
Rare discovery
The Kuiper Belt, a vast icy region beyond Neptune, is home to thousands of primitive objects left over from the early solar system. While binary systems are relatively common, triple systems are rare. The discovery of another could mean that these formations are more frequent than previously believed.
Keck’s powerful adaptive optics system played a key role in identifying Altjira’s unique structure. Researchers said the system has now entered an eclipsing phase, where its components will pass in front of one another. This event, lasting the next decade, will allow for further study, including upcoming observations by NASA’s James Webb Space Telescope.
“With objects this small and far away, the separation between the two inner members of the system is a fraction of a pixel on Hubble’s camera, so you have to use non-imaging methods to discover that it’s a triple,” Nelsen explained.
Scientists hope that continued observations will reveal more about how these rare triple systems form and whether they are a common feature of the Kuiper Belt.
