Overview
- Astronomers identified the trans‑Neptunian object 2026 ED138 in Vera C. Rubin Observatory data and archival images that trace its orbit to about 46 astronomical units from the Sun.
- Matthew Holman first flagged the moving source using software on Rubin data and teams recovered detections back to 2016 to reconstruct a 25‑degree inclined orbit.
- Initial brightness-based estimates place the object between roughly 600 and 1,500 kilometers across, a range that leaves its roundness and mass — key IAU criteria for dwarf‑planet status — unresolved.
- The team plans targeted follow‑up with infrared or thermal instruments, stellar occultation monitoring and searches for a satellite because those measurements will fix its size, albedo or mass.
- The find is one of Rubin’s earliest high‑profile results and shows the survey can reveal large, previously missed outer‑solar-system bodies hidden in the crowded Milky Way plane.