Overview
- Researchers led by Jamie Williams published a Nature Astronomy paper on Oct. 5 reporting a candidate second‑generation planet orbiting the white dwarf HS 0209+0832 about 270 light‑years away.
- Reanalysis of archival Hubble ultraviolet spectra, corroborated by FUSE data, revealed an unusually high abundance of niobium and other s‑process elements that point to material produced during the star’s red‑giant death phase falling onto the white dwarf.
- Independent TESS photometry shows a faint, regular 4.4‑day brightness modulation that the team interprets as a Jupiter‑sized gas giant in a tight orbit roughly 6 million kilometres from the white dwarf and likely losing atmosphere to the star.
- The authors argue the planet could have condensed from a disc made of the star’s own expelled, s‑process‑rich material and that forming such a disc likely required a companion to redirect ejecta, which helps explain why these worlds would be rare.
- The detection remains a candidate while the team pursues targeted follow‑ups with Hubble and Chandra and has requested JWST time to test for direct signs of atmospheric escape, accretion onto the white dwarf, and to rule out alternative explanations; confirmation would open a new channel for planet formation around stellar remnants.