In reading the European Space Organisation paper Lithium depletion in solar-like stars: no planet connection (Baumann et al. 2010), several conclusions based on their observations include:
- Lithium depletion in Sun-like stars is independent of having planets (an earlier theory), but rather is a function of the star's age. From the article:
For solar-like stars, the lithium vs age trends for planet-hosts and stars where no planets have been found are statistically identical. Thus, the presence of a planet does not influence the observed surface lithium abundance.
However, they observed that
A number of solar-like stars with unusually high lithium abundance for their age are present in the field.
and that these stars also have an anomalously low surface gravity.
What is the current theory as to why some Sun-like stars have a relatively high lithium abundance and low surface gravity?