Open in full screen mode This image mosaic shows the cluster of trapezoids and the interior of the Orion Nebula (Messier 42) captured by the instrument NIRcam of the James Webb Space Telescope.
Concretely, the detection of unknown stars was carried out from a mosaic composed of 712 images collected during a week of observation of the Trapezoid cluster located at the center of the nebula. /p>
What the scientists observed was surprising. They discovered many planetary-mass objects that don't fit the definition of a planet, that is, an object that orbits a star. They are, in a way, wandering planets. And about 9% of these objects form pairs.
A quote from Olivier Hernandez, astrophysicist and director of the Montreal Planetarium
We do not yet understand the physical processes that make it possible to form them. We don't have an answer. We will have to review our theoretical models […] to try to understand what is happening, confides the astrophysicist.
These objects were nicknamed JuMBOs, for Jupiter Mass Binary Objects, by the ESA team. If their nature remains to be determined, they could be aborted stars (brown dwarfs in particular) coming from regions of the nebula where the density of matter is insufficient for full-fledged stars to be born.
They could also have formed in the orbit of stars and then be expelled into interstellar space following cataclysmic events. The ejection hypothesis is currently favored, says Professor Mark McCaughrean, principal scientific advisor to the ESA, in a press release.
The question now is how two objects can be knocked out of a star's orbit at the same time.
Astrophysicists think that their formation would be relatively recent in astronomical terms: around 1 million years.
These objects would generally be very hot, the temperature on their surface could reach 1000°C, and their atmospheres would contain steam and methane.
< p class="StyledBodyHtmlParagraph-sc-48221190-4 hnvfyV">But without a host star, these worlds could also cool quickly as they move. So they might sometimes exhibit habitable temperatures, as they are gaseous, but their surfaces cannot harbor liquid water even during their brief temperate period, meaning they will never be habitable. /p>
ESA astrophysicists did not take an interest in this region of the sky randomly. Previous data collected by terrestrial telescopes and Hubble suggested the existence of nebulous objects in Orion.
We were looking for these very small objects and we found them!
A quote from Mark McCaughrean, Senior Scientific Advisor to the Agency European Space Agency
This is not the first time wandering planets have been discovered. In 2022, an international team of astrophysicists announced the detection of at least 70 planets of this type in a sector of our galaxy called the Rho Ophiuchi cloud. All these planets could, however, be born in different ways.
Open in full screen mode Artistic representation of a planet errante
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