SCIENCE GOALS AND OBJECTIVES: THE SUCCESS OF THE KEPLER SPACE TELESCOPE IN DETECTING PLANETS IN CIRCUMBINARY ORBITS STRONGLY SUGGESTS THAT PLANET FORMATION AROUND BINARY STARS IS ROBUST AND PLANETS OF A VARIETY OF SIZES AND ORBITAL CONFIGURATIONS MAY EXIST IN SUCH ENVIRONMENTS. ACCURATE MODELING OF KEPLER DATA HAS INDICATED THAT THE ORBITS OF MANY OF THESE PLANETS IS CLOSE TO THE BOUNDARY OF STABILITY AND THAT THEY RESIDE BETWEEN MAJOR RESONANCES WITH THEIR HOST BINARIES. A SURVEY OF THE CURRENTLY KNOWN CIRCUMBINARY PLANETS (CBPS) INDICATES THAT THE ORBITS OF MANY OF THESE OBJECTS ARE SLIGHTLY INCLINED AND THEY PRECESS WITH RATES THAT PLACE THEM OUT OF TRANSIT FOR THE MAJORITY OF THE TIME. THE LATTER STRONGLY SUGGESTS THAT NUMEROUS CBPS MAY EXIST IN NON-TRANSITING INCLINED ORBITS. THESE FINDINGS AND THE FACT THAT THE CURRENTLY KNOWN CBPS ARE SATURN- TO JUPITER-MASS COMBINED WITH UNSUCCESSFUL ATTEMPTS IN FORMING CBPS CLOSE TO THE ORBITAL STABILITY LIMIT HAS LENT STRONG SUPPORT TO THE IDEA THAT THESE PLANETS FORMED AT LARGE DISTANCES AND MIGRATED TO THEIR CURRENT LOCATIONS. TO EXPLAIN THE OBSERVATIONAL CHARACTERISTICS OF THESE BODIES AND IN ORDER TO BE ABLE TO QUANTIFY THE DETECTABILITY THOSE IN INCLINED ORBITS WE PROPOSE TO CARRY OUT A DETAILED GPU-BASED 3D STUDY OF THE MIGRATION AND DYNAMICAL EVOLUTION OF PLANETS IN CIRCUMBINARY DISKS TAKING INTO ACCOUNT THE EVOLUTION OF THE DISK AS WELL AS ITS INTERACTION WITH PLANETARY BODIES. IN BRIEF WE PROPOSE TO 1) STUDY THE EVOLUTION OF CIRCUMBINARY NEBULAE USING 3D RADIATIVE DISK MODELS 2) STUDY PLANET MIGRATION IN THESE DISKS FOR DIFFERENT ORBITAL INCLINATIONS AND MASSES OF THE PLANET 3) STUDY THE PROXIMITY OF CBPS TO THE BINARY STABILITY LIMIT AND THEIR CAPTURE BETWEEN MEAN-MOTION RESONANCES AND 4) ASSESS THE DETECTABILITY OF INCLINED CBPS THROUGH THE ECLIPSE TIMING VARIATION METHOD BY DETERMINING THE PROBABILITY OF THEIR CAPTURE IN STABLE ORBITS. WE HAVE ADDRESSED SOME OF THESE ISSUES BY DEVELOPING A COMPLETE 2D PLANET-DISK INTERACTION MODEL FOR CIRCUMBINARY SYSTEMS. HOWEVER RECENT DETECTIONS OF EPISODIC TRANSITS IN THREE CBPS NAMELY KEPLER 413B KEPLER 453B AND KEPLER 1647B HAVE INDICATED THAT IN GENERAL THE ORBITS OF PLANETS AND THEIR HOST BINARIES ARE NOT CO-PLANAR. THAT MEANS ANY TREATMENT OF PLANET-DISK INTERACTION AND PLANET MIGRATION IN CIRCUMBINARY SYSTEMS HAS TO BE CARRIED OUT IN 3D. WE PLAN TO USE THE NEW CODE FARGO3D DEVELOPED BY COLLABORATOR MASSET TO EXTEND OUR CURRENT MODELS OF PLANET-DISK INTERACTION IN CIRCUMBINARY SYSTEMS TO THREE DIMENSIONS. METHODOLOGY: TO PROPERLY CARRY OUT OUR PROPOSED TASKS WE START BY IMPLEMENTING A PROPER TREATMENT OF RADIATION TRANSPORT AND RADIATIVE COOLING IN 3D CIRCUMBINARY DISK MODELS. THE EVOLUTION AND DYNAMICAL BEHAVIOR OF THESE DISKS WILL BE STUDIED FOR DIFFERENT VALUES OF THEIR PARAMETERS AND THOSE OF THE BINARY. WE WILL STUDY THE DYNAMICS OF THE DISK NEAR THE CENTRAL BINARY AND PLACE CONSTRAINTS ON THE EXTENT OF THE INNER HOLE AND ITS ECCENTRICITY AS A FUNCTION OF THE DISK AND BINARY PARAMETERS. ONCE THE DISK MODELS HAVE BEEN DEVELOPED WE WILL SIMULATE THE MIGRATION OF PLANETS. WE WILL STUDY THE CONNECTION BETWEEN THE DISK AND PLANETS' PARAMETERS AND THEIR ROLE IN ESTABLISHING THE FINAL ORBITAL ARCHITECTURE OF THE SYSTEM. EMPHASIS WILL BE PLACED ON THE MASSES OF THE CIRCUMBINARY PLANETS TO INVESTIGATE THE OBSERVED OCCURRENCE RATE OF PLANETS AROUND THEIR HOST BINARIES. WE WILL IDENTIFY REGIONS OF CBP STABILITY AROUND THE HOST BINARY FOR INCLINED ORBITS AND EVALUATE THE AMPLITUDES OF ETVS INDUCED ON THE BINARY BY THESE BODIES. RELEVANCE TO THE GOALS OF XRP: OUR PROPOSED PROJECTS ARE IN DIRECT RELEVANCE TO THE GOALS OF NASA XRP. THEY INCLUDE COMPUTATIONAL MODELING OF DIFFERENT STAGES OF THE DYNAMICAL EVOLUTION OF CIRCUMBINARY DISKS AND THEIR EMBEDDED PLANETS. THE RESULTS OF THESE MODELS WILL DIRECTLY CONTRIBUTE TO OUR UNDERSTANDING OF THE ORIGINS OF EXOPLANETARY SYSTEMS.
$297,833FY2020National Aeronautics and Space AdministrationNASA
University Of Hawaii, Honolulu