¹M. Jura, ¹B. Klein, ¹S. Xu (许偲艺), ²E. D. Young
¹ Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1562, USA
² Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA 90095, USA

Relative to calcium, both strontium and barium are markedly enriched in Earth’s continental crust compared to the basaltic crusts of other differentiated rocky bodies within the solar system. Here, we both re-examine available archived Keck spectra to place upper bounds on n(Ba)/n(Ca) and revisit published results for n(Sr)/n(Ca) in two white dwarfs that have accreted rocky planetesimals. We find that at most only a small fraction of the pollution is from crustal material that has experienced the distinctive elemental enhancements induced by Earth-analog plate tectonics. In view of the intense theoretical interest in the physical structure of extrasolar rocky planets, this search should be extended to additional targets.

Reference
Jura M, Klein B, Xu S (许偲艺), Young ED (2014) A Pilot Search for Evidence of Extrasolar Earth-analog Plate Tectonics. Astrophysical Journal Letters 791, L29.

Link to Article [doi:10.1088/2041-8205/791/2/L29]