Astronomers using the Vera C. Rubin Observatory in Chile have found a large icy object beyond Neptune, provisionally designated 2026 ED138. Its diameter is estimated at 600 to 1,500 km, comparable to Ceres, and it orbits about 46 astronomical units from the Sun, farther out than Pluto's average of roughly 40 AU.
Astrophysicist Matthew Holman spotted it on October 13 in early-year data with a specialized search algorithm. The object sits close to the Milky Way's plane as seen from Earth, so it had blended into a dense star field. It was then found in 30 images across 20 nights between March and July, and archival data trace its orbit back to 2016.
It is a candidate, not a confirmed dwarf planet. Infrared observations are needed to measure its mass, density and shape, and formal recognition by the International Astronomical Union may take a long time.