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Rubin Team Reports Dwarf Planet Candidate 2026 ED138

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Read the story

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.

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.

Source: Vera C. Rubin Observatory, 2026-10-27. https://rubinobservatory.org/news/rubin-first-dwarf-planet-candidate

Read and practise

1. What happened on October 13?

   1. Matthew Holman identified the object in data
   2. The discovery was publicly announced
   3. Infrared observations confirmed its exact diameter

2. How could infrared measurements help the researchers?

   1. They could establish the date Holman identified the object
   2. They could narrow its estimated size and clarify its classification
   3. They could determine whether the announcement occurred on October 27

Your turn

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

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Read online: https://newsbylevels.com/news/rubin-dwarf-planet-candidate-ed138-october-2026/level-3/