Revisiting the 16 Cygni planet host at unprecedented precision and exploring automated tools for precise abundances

The binary system 16 Cygni is key in studies of the planet-star chemical composition connection, as only one of the stars is known to host a planet. This allows us to better assess the possible influence of planet interactions on the chemical composition of stars that are born from the same cloud and thus should have a similar abundance pattern. In our previous work, we found clear abundance differences for elements with Z ≤ 30 between both components of this system and a trend of these abundances as a function of the condensation temperature (Tc), which suggests a spectral chemical signature related to planet formation. In this work we show that our previous findings are still consistent even if we include more species, such as the volatile N and neutron capture elements (Z > 30). We report a slope with Tc of 1.56 ± 0.24 × 10−5 dex K−1, that is good agreement with our previous work. We also performed some tests using ARES and iSpec to measure automatically the equivalent width and found Tc slopes in reasonable agreement with our results as well. In addition, we determined abundances for Li and Be by spectral synthesis, finding that 16 Cyg A is richer not only in Li but also in Be, when compared to its companion. This may be evidence of planet engulfment, indicating that the Tc trend found in this binary system may be a chemical signature of planet accretion in the A component, rather than an imprint of the giant planet rocky core formation on 16 Cyg B.