Why are stars with more heavy elements more likely to have detectable gas giant planets?

Stars with higher concentrations of heavy elements—often referred to in astronomy as "metallicity"—are more likely to host detectable gas giant planets because these elements provide the necessary solid material for planetary cores to form efficiently.

According to the core-accretion model of planet formation, the development of a gas giant begins with the aggregation of solid grains into a massive core. Once this core reaches a critical mass—approximately 10 times the mass of Earth—its gravity becomes strong enough to rapidly attract and retain large amounts of hydrogen and helium from the surrounding solar nebula.1

In environments where heavy elements are more abundant, the density of solid material in the protoplanetary disk is higher. This increased availability of "building blocks" like silicates and ices allows for the faster and more frequent formation of these massive cores. Consequently, stars with higher metallicity provide a more favorable environment for the rapid growth required to trigger the runaway gas accretion that creates giant planets.12