White dwarfs may present amenable environments for life on planets formed within or migrated to their habitable zones, generating warmer surface environments than those of planets with main-sequence host stars, according to new research from the University of California, Irvine.
Exoplanets orbiting in the habitable zones of white dwarfs may harbor more clement conditions for life to compensate for the cooling and dimming of their host stars over time. Image credit: David A. Aguilar / CfA.
In the study, University of California, Irvine astronomer Aomawa Shields and colleagues compared the climates of water worlds with an Earth-like atmospheric composition orbiting in the habitable zone of two different types of stars: a white dwarf and the main-sequence K-dwarf star Kepler-62.
Using a 3D global climate computer model normally employed to study Earth’s environment, they found that the white dwarf exoplanet was much warmer than the Kepler-62 exoplanet despite analogous stellar energy distribution.
“While white dwarf stars may still give off some heat from residual nuclear activity in their outer layers, they no longer exhibit nuclear fusion at their cores,” Dr. Shields said.
“For this reason, not much consideration has been given to these stars’ ability to h
