Astronomers have discovered two pairs of Jupiter-mass "rogue" planets drifting through a young stellar nursery, a finding that bolsters the case for the existence of free-floating binary worlds.
Discovery Details
Astronomers report the discovery of two pairs of Jupiter-mass free-floating planets (FFPs) in the Lower Centaurus-Crux (LCC) association, a stellar nursery in the southern sky. The objects, designated VVVX-FFP-001 and VVVX-FFP-007, are each composed of two planet-mass objects (8 and 12 times Jupiter's mass respectively) separated by 3 and 180 times the Sun-Neptune distance. The finding was published April 24 in the journal Astronomy & Astrophysics by a team led by Claudio Cáceres of Andrés Bello University, Chile.
Background and Detection
In 2023, the James Webb Space Telescope (JWST) identified around 40 candidate Jupiter-mass binary objects (JuMBOs) in the Orion Nebula, but later reanalysis in 2024 suggested many were distant stars. The new objects were found by cross-matching archival near-infrared images from the VISTA telescope and visible-light data from the Gaia satellite.
The LCC association is about 15 million years old, making these planets young and more luminous at longer wavelengths.
Significance of the Find
The discovery supports the existence of binary free-floating planets. The team estimates such pairs account for about 2% of rogue planets in the LCC, lower than the 9% fraction claimed for Orion, suggesting the Orion sample may contain false positives.
"Tight binary FFPs could potentially retain liquid water and be habitable due to tidal heating, even without a host star."
Statements from the Research Team
Claudio Cáceres stated that he prefers the term "free-floating planetary-mass binaries" over JuMBOs, as the latter is not widely accepted in the literature. Co-author Dante Minniti expressed continued fascination with finding different kinds of planets.
Next Steps
The team plans further observations using the Very Large Telescope (VLT) to better characterize the objects.