How Jupiters Save or Destroy Inner Neptunes around Evolved Stars

SCHREIBER, MATTHIAS R.; CUADRA, JORGE; GIUPPONE, CRISTIAN A.; GUILERA, OCTAVIO M.; RONCO, MARÍA PAULA; VERAS, DIMITRI

The Astrophysical Journal

The Astrophysical Journal Letters

Lugar: Washington; Año: 2020 vol. 898

In about 6 Giga years our Sun will evolve into a red giant and finally end its life as a white dwarf.This stellar metamorphosis will occur to virtually all known host stars of exo-planetary systems andis therefore crucial for their final fate. It is clear that the innermost planets will be engulfed andevaporated during the giant phase and that planets located farther out will survive. However, thedestiny of planets in-between, at∼1−10 au, has not yet been investigated with a multi-planet tidaltreatment. We here combine for the first time multi-planet interactions, stellar evolution, and tidaleffects in anN-body code to study the evolution of a Neptune-Jupiter planetary system. We reportthat the fate of the Neptune-mass planet, located closer to the star than the Jupiter-mass planet, can bevery different from the fate of a single Neptune. The simultaneous effects of gravitational interactions,mass loss and tides can drive the planetary system towards mean motion resonances. Crossing theseresonances affects particularly the eccentricity of the Neptune and thereby also its fate, which can beengulfment, collision with the Jupiter-mass planet, ejection from the system, or survival at a largerseparation.