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arXiv · 2407.14190

Second-generation planet formation after tidal disruption from common envelope evolution

Luke Chamandy·Jason Nordhaus·Eric G. Blackman·Emily Wilson
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Abstract

We propose that certain white dwarf (WD) planets, such as WD 1856+534 b, may form out of material from a stellar companion that tidally disrupts from common envelope evolution with the WD progenitor star. The disrupted companion shreds into an accretion disc, out of which a gas giant protoplanet forms due to gravitational instability. To explore this scenario, we make use of detailed stellar evolution models consistent with WD 1856+534. The minimum mass companion that produces a gravitationally-unstable disc after tidal disruption is $\sim0.15\,\mathrm{M}_\odot$. In this scenario, WD 1856+534 b might have formed at or close to its present separation, in contrast to other proposed scenarios where it would have migrated in from a much larger separation. Planet formation from tidal disruption is a new channel for producing second-generation planets around WDs.

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Luke Chamandy, Jason Nordhaus, Eric G. Blackman, Emily Wilson. 2024-07-19. Second-generation planet formation after tidal disruption from common envelope evolution. https://doi.org/10.1017/pasa.2025.4

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