WORLDTECHRubin Observatory flags possible large dwarf planet ED138 beyond Pluto
The NSF–DOE Vera C. Rubin Observatory has picked out a large body in the outer solar system that scientists classify as a possible dwarf planet. Provisionally called ED138, the object circles beyond Pluto and, according to a preliminary analysis of the data, could be among the largest dwarf planet candidates found so far.
Discovery and provisional designation
The object was picked up by a researcher sifting through observations from the Simonyi Survey Telescope at the NSF–DOE Vera C. Rubin Observatory, the National Science Foundation reported. The International Astronomical Union's Minor Planet Center has assigned it the provisional designation ED138.
The findings were laid out at a gathering of the American Astronomical Society's Division for Planetary Sciences in Spokane, Washington. There, University of Washington astronomer Mario Jurić and Matthew Holman of the Harvard & Smithsonian Center for Astrophysics presented the results.
Why the object stayed hidden
ED138 lies in a stretch of sky close to the plane of the Milky Way, a zone packed with millions of stars. That crowded backdrop is the likely reason it went unrecognised for so long.
Rubin's repeated monitoring and sophisticated data algorithms made it possible to single out ED138 as it drifted through that dense field. The observatory's speed and its camera, the largest ever built, capture every visible change across the southern hemisphere sky.
Orbit and candidate status
A preliminary analysis places ED138 on a tilted orbit in the outer reaches of the solar system, well past Pluto. Should it be confirmed, it would take its place alongside the five other known dwarf planets: Pluto, Ceres, Eris, Haumea and Makemake.
Jurić, the solar system lead scientist on the Rubin team, said the observatory's capabilities made it possible to detect and characterise the object. ED138 is one of many solar system objects Rubin has discovered this year.
Open questions
- Will follow-up observations confirm ED138 as a dwarf planet?
- How large is ED138 once its size is measured more precisely?