Signatures of rocky debris accretion in AF-Type planet hosts

@misc{maldonado2026signatures,
  title = {{Signatures of rocky debris accretion in AF-Type planet hosts}},
  author = {J. Maldonado and I. Mendigutía and S. Barceló Forteza and G. M. Mirouh and B. Montesinos and E. Villaver},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.04790},
  eprint = {2609.04790},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.04790},
}

TY  - UNPB
TI  - Signatures of rocky debris accretion in AF-Type planet hosts
AU  - J. Maldonado
AU  - I. Mendigutía
AU  - S. Barceló Forteza
AU  - G. M. Mirouh
AU  - B. Montesinos
AU  - E. Villaver
PY  - 2026
DA  - 2026/09/04
PB  - arXiv
DO  - 10.48550/arxiv.2609.04790
UR  - https://arxiv.org/abs/2609.04790
AB  - The gas-giant planet-metallicity correlation plays a fundamental role in our understanding of planet formation. We determine in a homogeneous way the metallicity and individual abundances of a sample of A and early-F stars, with and without known planetary companions, and discuss their abundance distribution and trends. We find that stars with planets generally exhibit higher abundances of both iron-peak and volatile elements compared to stars without known planets although in most cases this tendency is not statistically significant. The C/O ratio remains similar between both samples, while the Mg/Si ratio is shifted towards higher values in the general planet host sample. When the sample is limited to fully radiative stars (spectral type earlier than F5), the statistical significance of carbon overabundances vanishes. In contrast, elements such as O and Ni remain significantly overabundant. The C/O and Mg/Si ratios in this radiative subsample are statistically indistinguishable from that of the comparison sample. The persistent overabundance of O and Ni, combined with C/O and Mg/Si ratios similar to those of stars without planets in fully radiative hosts, points to the ongoing surface pollution by volatile-poor, silicate-rich rocky debris, rather than the accretion of gas giants. These findings might position early-type main-sequence stars as a crucial dynamical missing link in the chemical life-cycle of planetary systems: bridging the initial dust-trapping phase in pre-main sequence transition discs, the dilution of this superficial pollution during the fully convective red giant phase, and the eventual dynamically-driven accretion of asteroid material observed in polluted white dwarfs
ER  -