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Rubin Team Reports Dwarf Planet Candidate 2026 ED138

Its brightness and distance suggest a large body, but the estimate remains uncertain.

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Science news editorial illustration for Rubin Observatory Finds Possible Dwarf Planet Beyond Pluto

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A in C. the , its is not . The of 2026 ED138 was on 27; had it in on 13.

The is 46 as from the as is. Its from 600 to 1,500 its is . the and it as a .

Source: Vera C. Rubin Observatory, 2026-10-27.

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Read and understand · 1/2What happened on October 13?

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Matthew Holman identified the object in data. Holman identified it on October 13; the announcement followed on October 27.

Clue: A distant object detected in Vera C. Rubin Observatory data could join the solar system's dwarf planets, although its classification is not yet established. The discovery of 2026 ED138 was announced on October 27; researcher Matthew Holman had identified it in data on October 13.

Read and understand · 2/2How could infrared measurements help the researchers?

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They could narrow its estimated size and clarify its classification. The article says infrared measurements could reduce size uncertainty and help establish its dwarf-planet status.

Clue: The body is currently about 46 times as far from the Sun as Earth is. Its estimated diameter ranges from 600 to 1,500 kilometres because its surface reflectivity is uncertain. Infrared measurements could narrow the size estimate and help establish whether it qualifies as a dwarf planet.

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Contrast the October 13 identification with the October 27 announcement and explain one remaining uncertainty.

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Holman identified the object in data on October 13; the discovery was announced on October 27. Its surface reflectivity is uncertain, so the diameter estimate is still a wide range.

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