A persistent question in exoplanet demographics is whether exoplanetary systems form from similar compositional building blocks to our own.
![Elemental abundance ratios for the Hypatia catalog stars in dex. Throughout, the white star shows solar values. A) [Mg/H] vs. [Fe/H], showing growth of an α nuclide compared with Fe. [Fe/H] is broadly taken as an indicator of time. The influence of Type Ia supernovae on galactic chemical evolution is indicated by the two arrows. B) Same data as [Mg/Fe] vs. [Fe/H]. The solid negatively sloping line shows the effect of induced ratio correlation due to Fe appearing on both axes. C) Same as B) but with contours showing 50, 80 and 95% levels for the chondritic (solid contours) and non-chondritic (dashed contours) populations of stars based on χ 2 ν tests. The larger points indicate stars that pass as chondritic and the smaller points do not pass. The non-chondritic population generally extends to lower metallicities than the chondritic stars. D) Ratios of lithophile elements only, showing no clear trend. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2023/06/AChondritic.png?resize=1200%2C720&ssl=1)
A persistent question in exoplanet demographics is whether exoplanetary systems form from similar compositional building blocks to our own.