Overview
- The discovery team publicly revealed 2026 ED138 at the American Astronomical Society Division for Planetary Sciences meeting in Spokane on Tuesday.
- Researchers found more than 30 detections in Vera C. Rubin Observatory images from March to July 2026 and located archival 'precovery' images dating back to 2016 to establish a reliable orbit.
- Orbit calculations place ED138 about 46 astronomical units from the Sun on a path tilted roughly 24–25 degrees and give it an orbital period near 281 years.
- Initial size estimates put the object between about 600 and 1,500 kilometers across, but that range depends on its unknown surface reflectivity so further thermal and light‑curve measurements are required.
- Teams are planning occultation campaigns, thermal observations and more imaging to test whether ED138 is in hydrostatic equilibrium and, if confirmed, it would join the small group of recognized dwarf planets.