Overview
- The team publicly announced the provisional discovery of 2026 ED138 on Oct. 27, 2026, at the American Astronomical Society’s Division for Planetary Sciences meeting in Spokane, Washington.
- Initial estimates place the object between about 600 and 1,500 kilometers across and orbiting roughly 46 astronomical units from the Sun with an inclination near 25 degrees.
- Researchers built the orbit by linking more than 30 Rubin observations from March–July 2026 with archival sightings dating back to 2016 using a specialized search pipeline developed at the Harvard Center for Astrophysics.
- The object escaped earlier detection because it lies in a dense Milky Way starfield whose starlight masked faint moving targets, and Rubin’s large mirror and wide field of view enabled the new identification.
- Confirming dwarf‑planet status will require follow‑up imaging and measurements to determine the body’s size, mass, and whether its self‑gravity has produced a near‑spherical shape, and further study could reveal more large objects hidden in crowded sky regions.