Palomar WIRC+POL

Weather Reports for Exoplanets and Brown Dwarfs with Precision Spectro-Polarimetry at Palomar

Understanding clouds and weather in exoplanet and brown dwarf atmospheres is one of the most active and fascinating areas of research in the fast-moving field of extra-solar planetary system science. The stakes are high for two main reasons: clouds represent a crucial element of exoplanets and brown dwarf atmosphere dynamics, but they can also form a veil preventing us from remote sensing molecular species deeper in the atmosphere. Emitted light from cloudy exoplanet atmospheres can be highly polarized, while starlight itself is virtually unpolarized. When two images taken with orthogonal polarization filters are subtracted, unpolarized starlight is removed, revealing the polarized astrophysical signal, and providing a significant contrast gain. Polarimetry is still largely unexploited despite its information-rich content. Indeed, the direction and amplitude of the emergent polarization signal as a function of color and time enable detailed characterization of the composition, morphology, and dynamics of the scattering clouds. We propose to integrate and commission a high precision near-infrared imaging low-resolution spectro-polarimeter mode for WIRC, the Prime focus wide-field infrared camera of the 200-inch Hale telescope on Mt Palomar, leveraging NASA-JPL and SBIR technological developments and advances in material science. The 200-inch is the largest equatorial-Cassegrain telescope in operation. This configuration is optimal for high precision polarimetry since it introduces little and stable instrumental polarization. This endeavor will ultimately help us break through the veil of clouds in exoplanets and brown dwarfs, provide new and unique capabilities to Palomar. It is also a technology pathfinder to future Keck and TMT instrumentation.

Click here for our white paper.

Co-investigators: Heather Knutson (Caltech, GPS), Rebecca Oppenheimer (AMNH), Ricky Nilsson (Caltech), Gautam Vasisht (JPL/Caltech), Eugene Serabyn (JPL/Caltech), Kaew Tinyamont (Caltech), Ming Zhao (NYT), Pushkar Kopparla (Caltech, GPS), Suniti Sanghavi (JPL/Caltech), Richard Dekany (Caltech), Roger Smith (Caltech), Dave Hale (Caltech), and A.N. Ramaprakash (IUCAA).

© Dimitri Mawet 2017