red-giant phase Archives - Astrobiology

llustration of possible system evolutionary histories under the Close-NE (a– c) and Wide-NE (d–f) models. Objects and orbits are not drawn to scale. Separations are representative values. (a) Initial configuration: close-in brown dwarf and wide-orbit planet. (b) Orbits expand due to host-star mass loss. AGB host star overflows Roche Lobe. Brown dwarf enters common envelope. (c) Common envelope ejected as brown dwarf orbit reduces to 0.2 au. Planetary orbit further expands. (d) Initial configuration: close-in planet and wide-orbit brown dwarf. (e) Orbits expand due to host-star mass loss. Brown dwarf and planet avoid interacting with the AGB host star. (f) Orbits continue to expand. -- astro-ph.EP

Exoplanets, -moons, -comets, Status Report, Stellar Cartography

An Earth-Mass Planet and a Brown Dwarf in Orbit Around a White Dwarf

by Keith CowingSeptember 6, 2024September 6, 2024

Terrestrial planets born beyond 1-3 AU have been theorized to avoid being engulfed during the red-giant phases of their host stars.