SIMBAD references

Context. Detailed abundance studies have reported different trends between samples of stars with and without planets, possibly related to the planet formation process. Whether these differences are still present between samples of stars with and without debris disk is still unclear.
Aims. We explore condensation temperature Tc trends in the unique binary system ζ¹ Ret -ζ² Ret to determine whether there is a depletion of refractories that could be related to the planet formation process. The star ζ² Ret hosts a debris disk which was detected by an IR excess and confirmed by direct imaging and numerical simulations, while ζ¹ Ret does not present IR excess or planets. These characteristics convert ζ² Ret in a remarkable system where their binary nature together with the strong similarity of both components allow us, for the first time, to achieve the highest possible abundance precision in this system.
Methods. We carried out a high-precision abundance determination in both components of the binary system via a line-by-line, strictly differential approach. First we used the Sun as a reference and then we used ζ² Ret. The stellar parameters Teff, logg, [Fe/H], and vturb were determined by imposing differential ionization and excitation equilibrium of FeI and FeII lines, with an updated version of the program FUNDPAR, together with plane-parallel local thermodynamic equilibrium ATLAS9 model atmospheres and the MOOG code. We then derived detailed abundances of 24 different species with equivalent widths and spectral synthesis with the MOOG program. The chemical patterns were compared with a recently calculated solar-twins Tc trend, and then mutually between both stars of the binary system. The rocky mass of depleted refractory material was estimated according to recent data.
Results. The star ζ¹ Ret is found to be slightly more metal rich than ζ² Ret by ∼0.02 dex. In the differential calculation of ζ¹ Ret using ζ² Ret as reference, the abundances of the refractory elements are higher than the volatile elements, and the trend of the refractory elements with Tc shows a positive slope. These results together show a lack of refractory elements in ζ² Ret (a debris-disk host) relative to ζ¹ Ret. The Tc trend would be in agreement with the proposed signature of planet formation rather than possible galactic chemical evolution or age effects, which are largely diminished here. Then, following the recent interpretation, we propose a scenario in which the refractory elements depleted in ζ² Ret are possibly locked up in the rocky material that orbits this star and produce the debris disk observed around this object. We estimated a lower limit of Mrock∼3M⊕ for the rocky mass of depleted material, which is compatible with rough estimations of 3-50M⊕ of a debris disk mass around a solar-type star.