Dozens of planet-sized objects have been discovered in the Orion Nebula via observations that could herald the existence of a new astronomical category.

The free-floating entities, which have been named Jupiter-mass binary objects, or Jumbos, appear in spectacular images taken by the James Webb space telescope. The objects are too small to be stars, but also defy the conventional definition of a planet because they are not in orbit around a parent star.

The discovery also appears to confound existing theories of star and planetary formation, which suggest it should not be possible to form Jupiter-sized objects through the process that gives rise to stars inside the clouds of dust and gas found in a nebula.