New Vera C. Rubin Telescope Spots Icy Candidate Beyond Pluto That Could Become a Dwarf Planet

A Potential New Addition to the Solar System

Scientists utilizing the newly operational Vera C. Rubin Observatory in Chile have identified an icy celestial object orbiting far beyond Pluto that is being evaluated as a potential new dwarf planet. Designated 2026 ED138, the candidate object was presented at a scientific meeting in Spokane, Washington, highlighting the early capabilities of the advanced telescope facility.

Researchers estimate that 2026 ED138 has a diameter ranging between roughly 600 and 1,500 kilometres. Its current orbit takes it about 46 times farther from the sun than Earth. For comparison, Pluto orbits the sun at an average distance of approximately 40 times that of Earth.

Context and Classification

If subsequent observations verify its characteristics, 2026 ED138 would join an exclusive group of five dwarf planets officially recognized by the International Astronomical Union (IAU), the global authority responsible for classifying celestial bodies. The currently recognized roster includes Pluto, Eris, Haumea, and Makemake—all located beyond Neptune—alongside Ceres, which resides in the main asteroid belt situated between Mars and Jupiter. Based on preliminary data, the newly spotted candidate would rank among the largest known dwarf planets.

To meet the IAU's formal definition of a dwarf planet, an object must possess sufficient mass for its own gravity to pull it into a round shape. While initial indicators suggest 2026 ED138 meets this mass criterion, further scientific verification is required.

Practical Implications and Verification

The discovery was made possible by the Vera C. Rubin Observatory, situated on the summit of the Cerro Pachón mountain in central Chile as a joint initiative of the U.S. National Science Foundation and the U.S. Department of Energy. Astrophysicist Matt Holman of the Center for Astrophysics, Harvard & Smithsonian, who initially spotted the object, noted that upcoming research will focus closely on determining its precise physical size and composition.

Because telescopes like the Rubin Observatory detect sunlight reflected off distant objects, determining exact dimensions can be challenging due to varying surface reflectivity—a smaller, highly reflective body can appear just as bright as a larger, less reflective one. To resolve this, researchers plan to utilize longer wavelengths using facilities such as the Atacama Large Millimeter/submillimeter Array (ALMA), also located in Chile, to detect thermal emissions directly from the object.

What Is Confirmed Versus Unknown

• Confirmed: An icy object designated 2026 ED138 has been discovered orbiting approximately 46 times farther from the sun than Earth, utilizing the Vera C. Rubin Observatory in Chile. The discovery was announced at a scientific meeting in Washington.
• Unknown: The precise physical size, surface composition, and definitive classification of 2026 ED138 as a dwarf planet remain unconfirmed pending further observations and data collection.

Readers interested in verifying the original announcement can review the official reporting through the Canadian Broadcasting Corporation at [CBC News](https://www.cbc.ca/news/science/possible-new-dwarf-planet-9.7399957).