An international team has identified 2026 ED138, a potential dwarf planet spotted in observations from the Vera C. Rubin Observatory. The object is estimated to be between 600 and 1,500 kilometres across and lies about 46 times farther from the Sun than Earth does. It takes roughly 281 Earth years to complete an orbit, which is tilted 25 degrees relative to the orbits of the planets.

The International Astronomical Union’s Minor Planet Center has confirmed the observations, but that does not settle the object’s classification. To count as a dwarf planet, an object must be massive enough for its own gravity to make it round, while not having cleared other objects from its orbital neighbourhood. 2026 ED138 is large and shares its orbital region, but its shape has not yet been established. More precise measurements, including infrared observations and light-curve analysis, are needed.

The object was noticed by scientist Matthew Holman while he was examining Rubin Observatory images. Its brightness and distance suggested it could be unusually large, and further checks found it in 30 images taken between March 4 and July 11, 2026. The observations showed it was not a one-off signal.

2026 ED138 is a trans-Neptunian object, located beyond Neptune in a region crowded with stars. That background made it difficult to pick out in images from other instruments, according to the report. The Rubin Observatory’s survey of the southern sky helped bring it to light.

The observatory’s long-term project began in June 2026. Its 3,200-megapixel camera takes detailed images about every 40 seconds, and the telescope is scheduled to scan the southern sky every few nights for 10 years. The resulting observations are intended to capture changes and moving objects over time.

There are currently five confirmed dwarf planets: Ceres, Pluto, Haumea, Makemake and Eris. Other objects, including Sedna, Gonggong, Orcus and Quaoar, remain candidates awaiting a decision. 2026 ED138 will also require further study before it can be added to the confirmed list.

Sources: Xataka.