Rubin Observatory Spots Dwarf Planet Candidate ED138 46 AU From the Sun
Updated
Updated · CNN · Oct 28
Rubin Observatory Spots Dwarf Planet Candidate ED138 46 AU From the Sun
3 articles · Updated · CNN · Oct 28
Summary
ED138 emerged from Vera C. Rubin Observatory data as a possible new dwarf planet beyond Pluto, with astronomers saying confirmation of its size will likely take a few months.
20 additional Rubin observations dating to March 2026, plus archival data stretching back 10 years, let researchers verify the object and map its orbit.
Estimated at 600 to 1,500 kilometers wide, ED138 would be larger than Ceres at the high end and sits about 46 astronomical units from the sun, classifying it as a trans-Neptunian object.
Rubin’s sky-surveying power helped reveal an object missed for years because it lies in the southern sky and against the crowded Milky Way star field.
If confirmed, ED138 would join the IAU’s five recognized dwarf planets and could signal that Rubin may uncover a handful of similarly large distant worlds.