Rubin Observatory Finds Possible New Dwarf Planet Beyond Pluto

Astronomers using the Vera C. Rubin Observatory have found an icy world beyond Pluto that could be large enough to count as a dwarf planet. If follow-up observations confirm it, the object, called 2026 ED138, would join a list that currently has only five members.

A Rare Find in the Outer Solar System

Matthew Holman of the Center for Astrophysics | Harvard & Smithsonian spotted the object on the evening of Oct. 13. He found it by running Rubin data through a search program he built with colleague Kevin Napier, which links detections of the same moving object across many images. The discovery was announced Oct. 27 by the International Astronomical Union’s Minor Planet Center and presented at a planetary science meeting in Spokane, Washington.

“Objects like this are very rare, so I immediately started checking whether I or the code had done something wrong,” Holman said in a release.