The GAPS Programme with HARPS-N at TNG. X. Differential abundances in the XO-2 planet hosting binary

Abstract

Binary stars hosting exoplanets are a unique laboratory where chemical tagging can be performed to measure with high accuracy the elemental abundances of both stellar components, with the aim to investigate the formation of planets and their subsequent evolution. Here, we present a high-precision differential abundance analysis of the XO-2 wide stellar binary based on high resolution HARPS-N@TNG spectra. Both components are very similar K-dwarfs and host planets. Since they formed presumably within the same molecular cloud, we expect they should possess the same initial elemental abundances. We investigate if the presence of planets can cause some chemical imprints in the stellar atmospheric abundances. We measure abundances of 25 elements for both stars with a range of condensation temperature $T_{\mathrm{C}}=40-1741$ K, achieving typical precisions of $\sim 0.07$ dex. The North component shows abundances in all elements higher by $+0.067\pm 0.032$ dex on average, with a mean difference of +0.078 dex for elements with $T_{\mathrm{C}}>800$ K. The significance of the XO-2N abundance difference relative to XO-2S is at the $2\sigma$ level for almost all elements. We discuss the possibility that this result could be interpreted as the signature of the ingestion of material by XO-2N or depletion in XO-2S due to locking of heavy elements by the planetary companions. We estimate a mass of several tens of $M_{\oplus }$ in heavy elements. The difference in abundances between XO-2N and XO-2S shows a positive correlation with the condensation temperatures of the elements, with a slope of $(4.7\pm 0.9)\times 10^{-5}$ dex K${}^{-1}$, which could mean that both components have not formed terrestrial planets, but that first experienced the accretion of rocky core interior to the subsequent giant planets.

10 pages, 5 figures, accepted by Astronomy & Astrophysics. Numbering of the series changed

References in corpus (22)

• Dust Masses, PAH Abundances, and Starlight Intensities in the SINGS Galaxy Sample
• Toward a Deterministic Model of Planetary Formation V. Accumulation Near the Ice Line
• The elemental composition of the Sun II. The iron group elements Sc to Ni
• The elemental composition of the Sun I. The intermediate mass elements Na to Ca
• The elemental composition of the Sun III. The heavy elements Cu to Th
• Asteroseismology of the solar analogs 16 Cyg A & B from Kepler observations
• XO-2b: Transiting Hot Jupiter in a Metal-rich Common Proper Motion Binary
• Line lists for the A2PI-X2Sigma+ (red) and {B2Sigma+-X2Sigma} (violet) Systems of CN, 13C14N, and 12C15N, and Application to Astronomical Spectra
• High eccentricity planets from the Anglo-Australian Planet Search
• The dissimilar chemical composition of the planet-hosting stars of the XO-2 binary system
• HAT-P-5b: A Jupiter-like hot Jupiter Transiting a Bright Star
• On the origin of stars with and without planets. Tc trends and clues to Galactic evolution
• High precision abundances in the 16 Cyg binary system: a signature of the rocky core in the giant planet
• A high precision chemical abundance analysis of the HAT-P-1 stellar binary: constraints on planet formation
• Abundance Differences Between Exoplanet Binary Host Stars XO-2N and XO-2S -- Dependence on Stellar Parameters
• Searching for signatures of planet formation in stars with circumstellar debris discs
• WASP-94 A and B planets: hot-Jupiter cousins in a twin-star system
• Detailed Abundances of Planet-Hosting Wide Binaries. I. Did Planet Formation Imprint Chemical Signatures in the Atmospheres of HD 20782/81?
• The GAPS Programme with HARPS-N@TNG V. A comprehensive analysis of the XO-2 stellar and planetary systems
• The GAPS programme with HARPS-N@TNG IV: A planetary system around XO-2S
• Planets in binary systems: is the present configuration indicative of the formation process?
• Discovering the Growth Histories of Exoplanets: The Saturn Analog HD 149026b

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