Overview
- The research team published a Nature Astronomy paper on Monday reporting a candidate planet around the white dwarf HS 0209+0832 based on archival Hubble spectra and TESS photometry.
- Reanalysis of 1999 Hubble ultraviolet data revealed extreme amounts of niobium and other s-process elements in the white dwarf’s atmosphere that ordinary, first-generation planetary debris cannot explain.
- Independent FUSE ultraviolet data and a faint, periodic 4.4-day brightness signal in TESS data support the interpretation of a close-in, Jupiter-sized gas giant that may be losing atmosphere onto the white dwarf.
- The authors propose the planet condensed from a disk of material the star expelled as it died, a process that likely required asymmetric mass loss or a companion to trap ejecta, which helps explain why such 'phoenix' planets should be rare.
- To test and confirm the candidate the team has scheduled targeted follow-up with Hubble and Chandra and requested JWST time, and a confirmed detection would open a new way to search for second-generation planets around white dwarfs.