Place: 4421 Sterling Hall, Coffee and cookies 3:30 PM, Talk begins 3:45 PM
Speaker: Andrew Vanderburg, University of Texas
Abstract: Over the past thirty years, astronomers have made extraordinary progress in detecting planets around other stars. We now know that stars commonly host planets with a wider range of physical properties and system architectures than exist in our own solar system, and that planets likely outnumber stars in our galactic neighborhood. Now, planet detection technologies have advanced to the point where the direct detection of Earth-like exoplanets to search for biosignatures is within reach, and NASA is studying two space mission concepts with these goals in mind to potentially launch in the late 2030s. However, before this can happen, significant gaps in our knowledge of exoplanets must be covered so that these missions can be designed and their data can be interpreted. In my talk, I will describe work to fill in these gaps in our understanding of exoplanets. In particular, I will show how measurements of the bulk densities of small planets can constrain the planets' bulk composition and the presence of thick hydrogen/helium atmospheres. I will show how observations of white dwarf stars can reveal the elemental composition of rocky planets and the path towards using white dwarfs to learn about the compositional diversity of planets around other stars. Finally, I will show how modern artificial intelligence techniques can help measure precisely how common Earth analogs are, a crucial input parameter for designing missions to characterize Earth analogs.