A Chondritic Solar Neighborhood

Abstract A persistent question in exoplanet demographics is whether exoplanetary systems form from similar compositional building blocks to our own. Polluted white dwarf stars offer a unique way address this question, as they provide measurements of the bulk compositions material. We present statistical analysis rocks polluting oxygen-bearing dwarfs and compare their solar system. find that majority extrasolar are consistent with composition typical chondrites. Measurement uncertainties prevent distinguishing between chondrites Earth but do permit detecting differences chondritic basaltic or continental crust. no evidence crust among polluted dwarfs. show nature also supported by local stars. While galactic chemical evolution results variations relative abundances rock-forming elements spatially temporally on galaxy-wide scales, current sample sufficiently young close not affected process. conclude exotic required explain observed rock types around stellar neighborhood generally due significant initial protoplanetary disks. Nonetheless, there observations planets formed first several billion years Galaxy have lower metal core fractions compared average.