Implications of the spectroscopic abundances in {\alpha} Centauri A and B

TL;DR

This study combines multiple spectroscopic abundance measurements of { extalpha} Centauri A and B to analyze their chemical composition, suggesting they formed from similar material and that A might host an undiscovered planet.

Contribution

It provides a combined analysis of abundance data reducing systematic effects, revealing similarities with the Sun and potential planetary presence around { extalpha} Centauri A.

Findings

{ extalpha} Cen system and Sun likely formed from same material

{ extalpha} Cen A and B have near-solar abundance ratios

Possible indication of an undiscovered planet around { extalpha} Cen A

Abstract

Regardless of their close proximity, abundance measurements for both stars in {\alpha} Centauri by different groups have led to varying results. We have chosen to combine the abundance ratios from five similar data sets in order to reduce systematic effects that may have caused inconsistencies. With these collated relative abundance measurements, we find that the {\alpha} Cen system and the Sun were likely formed from the same material, despite the [Fe/H] enrichment observed in the {\alpha} Cen binaries: 0.28 and 0.31 dex, respectively. Both {\alpha} Centauri A and B exhibit relative abundance ratios that are generally solar, with the mean at 0.002 and 0.03 dex, respectively. The refractory elements (condensation temperature > 900 K) in each have a mean of -0.02 and 0.01 dex and a 1{\sigma} uncertainty of 0.09 and 0.11 dex, respectively. Given the trends seen when analyzing the refractory abundances [X/Fe] with condensation temperature, we find it possible that {\alpha} Centauri A may host a yet undiscovered planet.