http://arxiv.org/abs/1311.2417
We explore the relations between physical and orbital properties of planets and properties of their host stars to identify the main observable signatures of the formation and evolution processes of planetary systems. We use a large sample of FGK dwarf planet hosts with stellar parameters derived in a homogeneous way from the SWEET-Cat database to study the relation between stellar metallicity and position of planets in the period-mass diagram. In the second part we use all the RV detected planets orbiting FGK stars to explore the role of planet-disk and planet-planet interaction on the evolution of orbital properties of planets with masses above 1MJup. We show that planets orbiting metal-poor stars have longer periods than those in the metal-rich systems. This trend is valid for masses at least from 10MEarth to 4MJup. Earth-like planets orbiting metal-rich stars always show shorter periods (less than 20 days) than those orbiting metal-poor stars. We also find statistically significant evidence that very high mass giants (with mass above 4MJup) have on average more eccentric orbits than giant planets with lower mass. Finally, we show that of the planets with masses above 4MJup the eccentricity tends to be lower for those with shorter periods. Our result suggest that there is a mechanism responsible for a “discrimination” of planets in the P-MP diagram operating for a wide range of planetary mass which depends on the metallicity of the system. One possibility is that planets in metal-poor disks form further out from their central star and/or they form later and do not have time to migrate as much as the planets in the metal-rich systems. The trends and dependencies obtained for very high-mass planetary systems suggest that planet-disk interaction is a very important and orbit-shaping mechanism for the planets in the high-mass domain.(Shortened).
Tue, 12 Nov 13
48/63
You must be logged in to post a comment.