White dwarf
Stellar remnant of low- and intermediate-mass stars after the end of their main-sequence and red-giant phases. The Sun will end as a white dwarf in ~5 Gyr.
Relevance to UAP / astrobiology vault
- Late-system architecture: white dwarfs preserve outer planetary remnants while engulfing or destabilizing inner ones — a useful boundary condition for studies of post-main-sequence planet survival.
- wd-0806b orbits a white dwarf at 2,500 AU and is the second-coldest directly imaged exoplanet known. JWST atmosphere characterization in 2026 (see src-aas-nova-wd-0806b-atmosphere-2026-04) yielded the first observational altitude-dependent K_zz in an exoplanet atmosphere.
- Dyson swarm host candidate: a 2026 study finds white dwarfs’ compact size makes them highly material-efficient Dyson-swarm hosts, with a swarm potentially orbiting just millions of km above the surface and producing a distinctive cold-infrared signature (src-dyson-sphere-cold-stars-technosignature-2026-07).