Overview
- The free-floating object Cha 1107-7626, about 5–10 times Jupiter’s mass and roughly 620–630 light-years away, reached a peak accretion rate of around 6 billion metric tons per second in August 2025.
- The outburst was about eight times stronger than in the preceding months and marks the fastest planet-scale growth ever recorded.
- Spectra taken from late June through August show hotter, brighter emission and the temporary appearance of water vapor in the surrounding disk that was absent before the burst.
- Signatures indicate material was funneled along magnetic fields, mirroring rare growth episodes in young stars and informing how some rogue planets may form.
- Findings draw on ESO’s Very Large Telescope with support from JWST archives and SINFONI, are published in Astrophysical Journal Letters, and follow-up monitoring is planned with archival hints of a similar episode in 2016.