High-precision abundances for stars with planets

The maximum amplitude of depletion increases with effective temperature from 5650K to 5950K, while it appears to be constant for warmer stars (up to 6300K). The depletions observed in solar twin stars have a maximum amplitude that is very similar to that seen here for both of our samples. Gas giant planet formation alone cannot explain the observed distributions of refractory-element depletions, leaving the formation of rocky material as a more likely explanation of our observations.

More rocky material is necessary to explain the data of solar twins than metal-rich stars, and less for warm stars. However, the sizes of the stars' convective envelopes at the time of planet formation could be regulating these amplitudes. Our results could be explained if disk lifetimes were shorter in more massive stars, as independent observations indeed seem to suggest.