Exploring the Diversity of Exoplanets Bulk Densities in multi-parameter space

This project is proposed by a consortium of three closely working German teams located at DLR Berlin-Adlershof (DLR-EPA), the Thüringer Landessternwarte Tautenburg (TLS) and the Rheinisches Institut für Umweltforschung at the University Cologne in Köln (RIU-PF) who have a considerable experience in transit detection in stellar light curves (RIU, DLR), in radial velocity measurements and interpretation (TLS) and in transit modelling (DLR). Unlike other efforts in the community all of this expertise is maintained in a single working group. This proposal aims at understanding the structures found in the planet densities as a function of several planetary parameters (mass,  scaled distance, insolation, etc.), aims at discovering many more planets in the mass range of interest and that it can provide clues as to the formation and evolution of exoplanets and will therefore make a substantial contribution to the fundamental question posed by SPP-1992. This proposal also connects to questions raised during the first phase of SPP1992 from our own observations and research: (i) recompute precisely and consistently the stellar, planetary and orbital properties of planetary systems with measured mass as a base to achieve the objectives; (ii) understand the distribution of the low (3-11 Mearth) and intermediate (11-100 Mearth) mass planets in the mass-density diagram. Can a third parameter (insolation, scaled semi-major axis etc)  help to explain the distribution?; (iii) understand from the mass-density diagram and planet detections how the ice planets between low mass planets and giant planets form; (iv) define the boundary between giant planets and Brown Dwarfs considering  their properties (mass-density relationship, formation, interiors etc.); (v) Define more precisely the transition mass between Brown Dwarfs and stars from new discoveries; (vi) study ultra-short period planets: survival expectancy under tides, and mass loss by evaporation, shape deformations which may give clues on their formation. The previous funding period enabled us to complete our K2 activities and to focus on the study of TESS transit candidates. During the next funding period we want to proceed with the science exploitation of TESS and CHEOPS light curves. This work will also prepare this consortium and the German community for exoplanet science in the PLATO era.