Overview
- Astronomers announced the detection of a new outer‑Solar‑System object provisionally designated 2026 ED138 that the Vera C. Rubin Observatory flagged as a dwarf‑planet candidate.
- The discovery was first singled out in Rubin data on October 13 and publicly presented at scientific meetings on October 27–28 after teams recovered detections going back to 2016.
- Initial brightness-based estimates put ED138 between about 600 and 1,500 kilometers across, but that range is wide because its surface reflectivity is unknown.
- ED138 orbits roughly 46 astronomical units from the Sun on a path tilted about 24–25 degrees to the solar system plane, a tilt that points to past perturbations likely from Neptune.
- Follow-up work now underway includes stellar occultation campaigns and thermal infrared observations with facilities such as ALMA or JWST to measure diameter, shape and albedo so the IAU can consider formal classification.