Mulders, Gijs D.Gijs D.MuldersPascucci, IlariaIlariaPascucciApai, DánielDánielApaiFRASCA, AntonioAntonioFRASCAMolenda-Żakowicz, JoannaJoannaMolenda-Żakowicz2021-04-122021-04-1220160004-6256http://hdl.handle.net/20.500.12386/30734Host star metallicity provides a measure of the conditions in protoplanetary disks at the time of planet formation. Using a sample of over 20,000 Kepler stars with spectroscopic metallicities from the LAMOST survey, we explore how the exoplanet population depends on host star metallicity as a function of orbital period and planet size. We find that exoplanets with orbital periods less than 10 days are preferentially found around metal-rich stars ([Fe/H] ≃ 0.15 ± 0.05 dex). The occurrence rates of these hot exoplanets increases to ∼30% for super-solar metallicity stars from ∼10% for stars with a sub-solar metallicity. Cooler exoplanets, which reside at longer orbital periods and constitute the bulk of the exoplanet population with an occurrence rate of ≳90%, have host star metallicities consistent with solar. At short orbital periods, P\lt 10 days, the difference in host star metallicity is largest for hot rocky planets (\lt 1.7 {R}\oplus ), where the metallicity difference is [Fe/H] ≃ 0.25 ± 0.07 dex. The excess of hot rocky planets around metal-rich stars implies they either share a formation mechanism with hot Jupiters, or trace a planet trap at the protoplanetary disk inner edge, which is metallicity dependent. We do not find statistically significant evidence for a previously identified trend that small planets toward the habitable zone are preferentially found around low-metallicity stars. Refuting or confirming this trend requires a larger sample of spectroscopic metallicities.STAMPAenArticle10.3847/0004-6256/152/6/1872-s2.0-85009152620000389057100005https://iopscience.iop.org/article/10.3847/0004-6256/152/6/1872016AJ....152..187MFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering