Theoretical planetary mass spectra - a prediction for COROT

Abstract

The satellite COROT will search for close-in exoplanets around a few thousand stars using the transit search method. The COROT mission holds the promise of detecting numerous exoplanets. Together with radial velocity follow-up observations, the masses of the detected planets will be known. We have devised a method for predicting the expected planetary populations and compared it to the already known exoplanets. Our method works by looking at all hydrostatic envelope solutions of giant gas planets that could possibly exist in arbitrary planetary nebulae and comparing the relative abundance of different masses. We have completed the first such survey of hydrostatic equilibria in an orbital range covering periods of 1 to 50 d. Statistical analysis of the calculated envelopes suggests division into three classes of giant planets that are distinguished by orbital separation. We term them using classes G (close-in), H, and J (large separation). Each class has distinct properties such as a typical mass range. Furthermore, the division between classes H and J appears to mark important changes in the formation: for close-in planets (classes G and H) the concept of a critical core-mass is meaningless while it is important for class J. This result needs confirmation by future dynamical analysis. © 2007 The Author. Journal compilation © 2007 RAS.