Investigating the planet-metallicity correlation for hot Jupiters

Abstract

We investigate the giant planet-metallicity correlation for a homogeneous, unbiased set of 217 hot Jupiters taken from nearly 15 yr of wide-field ground-based surveys. We compare the host star metallicity to that of field stars using the Besançon Galaxy model, allowing for a metallicity measurement offset between the two sets. We find that hot Jupiters preferentially orbit metal-rich stars. However, we find the correlation consistent, though marginally weaker, for hot Jupiters (β = 0.71+0.56 -0.34) than it is for other longer period gas giant planets from radial velocity surveys. This suggests that the population of hot Jupiters probably formed in a similar process to other gas giant planets, and differ only in their migration histories.