Astronomers using the James Webb Space Telescope have made a remarkable discovery in the NGC 1333 star cluster â six new worlds that resemble planets but formed like stars. These rogue worlds, ranging from five to 15 times the mass of Jupiter, do not orbit a star, indicating that they likely originated from the collapse of dust and gas clouds, similar to the birth of stars like our sun. Referred to as brown dwarfs or failed stars, these objects are not massive enough to sustain hydrogen fusion.
Lead researcher Ray Jayawardhana from Johns Hopkins University in Maryland notes, “In some ways, whatâs most striking is what we didnât find. We didnât find anything below five Jupiter masses, despite the fact that we had the sensitivity to do so.” This suggests that brown dwarfs may not form at smaller masses, making these newly discovered objects the smallest to form like stars. The team estimates that planetary mass brown dwarfs make up approximately 10% of the objects in the NGC 1333 cluster, a higher proportion than expected based on current star formation models.
One of the brown dwarfs stands out for its peculiar characteristics â it possesses a ring of dust similar to the one that gave rise to planets in our solar system. This particular world, weighing about five times the mass of Jupiter, is the smallest known object with such a ring. It may signify the early stages of a miniature planetary system surrounding a failed star. However, the dim glow of these brown dwarfs, mainly in the infrared spectrum, suggests that any planets forming around them would eventually freeze over as the brown dwarf fades into obscurity, rendering these worlds unsuitable for harboring life.
The findings, soon to be published in The Astronomical Journal, shed light on the enigmatic nature of rogue worlds and raise questions about the mechanisms driving their formation. Further research may uncover additional insights into these fascinating celestial objects.
