Rubin Observatory has identified a bright object beyond Pluto as a dwarf-planet candidate. Its orbit emerges from new detections combined with older images, reaching back more than a decade. Its estimated size remains broad because surface reflectivity is uncertain; additional observations are needed before the distant body can receive a confirmed classification.
Vera C. Rubin Observatory in Chile has identified 2026 ED138, a distant object beyond Pluto, as its first dwarf-planet candidate. Its brightness and distance suggest a large icy body, while its classification remains unsettled. Researchers established the orbit by connecting detections across different dates and finding the object in archival images, extending its known trajectory well beyond the new observations.[1], [2]
Rubin recorded the object thirty times over twenty nights between March and July. Older images from the Dark Energy Camera on Chile’s Blanco telescope took the orbit reconstruction back to 2016. The candidate currently lies about 46 astronomical units from the Sun; one such unit is the average Earth–Sun distance. Its orbit tilts almost 25 degrees relative to the Solar System’s plane.[1]
The estimated diameter ranges from 600 to 1,500 kilometers. That range depends on assumptions about surface reflectivity as well as measured brightness and distance. Infrared observations could narrow the estimate. Dwarf-planet status also requires enough mass for gravity to make the body approximately round. The International Astronomical Union has yet to classify this candidate, so discovery of the object precedes confirmation of its nature.[1]
