A Theory of Extrasolar Giant Planets

We present a broad suite of models of extrasolar giant planets (EGP's), ranging in mass from 0.3 to 15 Jupiter masses. The models predict luminosity (both reflected and emitted) as a function of age, mass, deuterium abundance and distance from parent stars of various spectral type. We also explore the effects of helium mass fraction, rotation rate and the presence of a rock-ice core. The models incorporate the most accurate available equation of state for the interior, including a new theory for the enhancement of deuterium fusion by electron screening which is potentially important in these low mass objects. The results of our calculations reveal the enormous sensitivity of EGP's to the presence of the parent star, particularly for G and earlier spectral types. They also show a strong sensitivity of the flux contrast in the mid-infrared between parent star and EGP to the mass and age of the EGP's. We interpret our results in terms of search strategies for ground- and space-based observatories in place or anticipated in the near future.