Based on detailed spectroscopic analysis of over 1000 F, G, and K stars in the Keck, AAT, and Lick planet search programs, we find that the probability of detecting giant planets with periods less than 4 years and velocity amplitudes greater than 30 m/s increases as the square of the iron abundance, rising smoothly from 3% at [Fe/H]=0.0 to 12% at [Fe/H]=0.3. Our uniform spectroscopic analysis of the entire sample, including stars without planets, is the best way to characterize and remove metallicity biases in the sample. By examining metallicity distributions of stars with and without planets as a function of stellar convection zone mass and planetary orbital properties, we conclude that high metallicity enhances giant planet formation. We find no evidence that stars with giant planets have higher metallicity because they have accreted metal-rich debris associated with the planet formation process.

Refreshments will be served in the Steward Observatory lobby at 3:30pm.