Overview
- Researchers using the Vera C. Rubin Observatory flagged a bright outer‑Solar‑System object provisionally named 2026 ED138 after finding 2026 detections and tracing its path in archived images back to 2016.
- ED138 orbits at roughly 46 astronomical units from the Sun and has a crude diameter range of 600 to 1,500 kilometers based on current brightness and reflectivity estimates.
- Scientists plan thermal observations with facilities such as ALMA and additional imaging to measure ED138’s physical size and shape, because only a nearly spherical shape meets the IAU definition of a dwarf planet.
- If follow‑up data show ED138 is sufficiently round, it would join Ceres, Pluto, Eris, Haumea and Makemake as the sixth IAU‑recognized dwarf planet, after which a permanent number and a name would be assigned over time.
- The find highlights Rubin’s wide, deep, fast survey power and points to past blind spots in searches near the Milky Way’s dense star fields and the southern sky, suggesting more large trans‑Neptunian objects may still be waiting to be found.