Old Puzzle, New Insights: A Lithium-rich Giant Quietly Burning Helium in Its Core

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About 1% of giant stars have been shown to have large surface Li abundances, which is unexpected according to standard stellar evolution models. Several scenarios for lithium production have been proposed, but it is still unclear why these Li-rich giants exist. A missing piece in this puzzle is the knowledge of the exact stage of evolution of these stars. Using low-and-high-resolution spectroscopic observations, we have undertaken a survey of lithium-rich giants in the Kepler field. In this Letter, we report the finding of the first confirmed Li-rich core-helium-burning giant, as revealed by asteroseismic analysis. The evolutionary timescales constrained by its mass suggest that Li production most likely took place through non-canonical mixing at the RGB tip, possibly during the helium flash.


  • V. Silva Aguirre
  • Gregory Ruchti
  • S. Hekker
  • S. Cassisi
  • J. Christensen-Dalsgaard
  • A. Datta
  • A. Jendreieck
  • J. Jessen-Hansen
  • A. Mazumdar
  • B. Mosser
  • D. Stello
  • P. G. Beck
  • J. de Ridder
Enheter & grupper

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Astronomi, astrofysik och kosmologi


TidskriftAstrophysical Journal Letters
Utgåva nummer1
StatusPublished - 2014
Peer review utfördJa