Special Physics Colloquium: Thursday, January 16th, 2020: Characterizing Directly Imaged Planets in Polarized Light

Event Date: 

Thursday, January 16, 2020 - 2:00pm

Event Location: 

  • Broida Hall
  • Room 3302
  • Special Physics Colloquium

Current high-contrast imagers have enabled direct characterization of the atmospheres of young Jupiter-mass planets through multi-wavelength and spectroscopic measurements using light emitted by the planets themselves. The interpretation of these measurements relies on fitting the observations to atmospheric models, allowing us to estimate basic physical properties of these objects (e.g. effective temperature and surface gravity). However, comparisons between the observed data and model spectra have revealed that our understanding of cloud properties is incomplete and limits our ability to accurately infer the physical characteristics of these objects. Polarized light emitted by these objects provides an alternative observable that is sensitive to cloud properties and can provide critical inputs to these models. In this talk I will provide an introduction to my work on using polarimetry to learn more about cloud properties in directly imaged planets and their free-floating analogs, brown dwarfs. I will also describe recent and ongoing instrument upgrades that I have been leading that will provide new polarimetric capabilities and open the door to a wide range of new polarimetric cloud studies. Finally, I will discuss how I hope to use polarimetry for both planet characterization and detection in the context of reflected light planets imaged with the Thirty Meter Telescope. 

Maxwell Millar-Blanchaer, CalTech