Exoplanet Genetics: What Host Star Chemical Abundances Reveal about Exoplanets
Through the process of star and planet formation, we think that the chemical abundances, or ``genes’’, of host stars are passed on to their orbiting planets. One prominent example of this is the giant planet-metallicity (iron abundance) correlation, but could other stellar ``genes’’ help explain the growing menagerie of exoplanets? Particularly interesting is the relative importance of C, O, Mg, and Si – for instance, are giant planet cores dominated by ice-forming or rock-forming elements? The ratios of these elements in terrestrial planets also control their interior structure and mineralogy, and can thus affect habitability. I will present results of ongoing spectroscopic studies of host stars to investigate how/to what extent planet composition is dependent on host star properties. I will highlight the importance of binary host stars in answering this question, new exoplanet detections from the Carnegie planet-finding collaboration, and the role that upcoming facilities can play in understanding the diversity of planets in the Galaxy.
Through the process of star and planet formation, we think that the chemical abundances, or ``genes’’, of host stars are passed on to their orbiting planets. One prominent example of this is the giant planet-metallicity (iron abundance) correlation, but could other stellar ``genes’’ help explain the growing menagerie of exoplanets? Particularly interesting is the relative importance of C, O, Mg, and Si – for instance, are giant planet cores dominated by ice-forming or rock-forming elements? The ratios of these elements in terrestrial planets also control their interior structure and mineralogy, and can thus affect habitability. I will present results of ongoing spectroscopic studies of host stars to investigate how/to what extent planet composition is dependent on host star properties. I will highlight the importance of binary host stars in answering this question, new exoplanet detections from the Carnegie planet-finding collaboration, and the role that upcoming facilities can play in understanding the diversity of planets in the Galaxy.