Collaborative Research: High Contrast Imaging at the Photon Noise Limit: On-Sky Validation of Speckle Reconstruction from WFS Telemetry

Imaging extrasolar planets is challenging. Planets are typically one hundred thousand to ten billion times fainter than their host stars. Taking pictures of such planets requires nearly perfect control of light. Starlight is blocked using optical devices called "coronagraphs". Ground-based telescopes must deal with the additional problem of turbulence in the Earth's atmosphere. Turbulence causes the stars to twinkle, and telescopes remove this twinkle using a technique called "Adaptive Optics". Finally, image processing is performed to find the exoplanet signal in the noise. Current instruments do not image the faintest possible planets because they are limited by “speckles”, which are created by imperfections in all of the above steps. However not all the available information is currently used when analyzing such images. Nearly all image processing methods use only the science images themselves. This creates many biases and artifacts. This is especially true close to the star, where most planets can be found. The goal of this project is to find more planets by using all the combined information. Software will be written for two existing instruments, which will be used by astronomers to analyze their images. This software will be written to be easy to use and made freely available to astronomers. Students will be involved at both participating institutions. Direct imaging characterization of exoplanets has so far been limited to young, hot, and massive planets orbiting relatively far from their stars. Such planets are observable due to their intrinsic self-luminosity generated as they continue to cool after formation. Many more planets are observable if the inner working angle can be improved. Moreover, improving the sensitivity limit of high-contrast imaging will enable the characterization of fainter, lower-mass planets. The key to enabling more sensitive post-processing is to use the data simultaneously recorded by the suite of wavefront sensors (WFSs) in a modern high-contrast imaging system. These include the main high-order WFS as well as coronagraph low-order and focal plane WFS. The investigators, with the assistance of a post-doctoral researcher, will implement algorithms based on existing proofs of concept, test and validate these algorithms with lab and on-sky data, and deploy the software systems on the MagAO-X and SCExAO instruments. These two extreme-AO coronagraphic instruments share a common software framework and there is collaboration between the instrument teams. This system will be deployed so that users can use it to reduce their data to achieve the highest possible sensitivity at small separations. Making a telemetry-based post-processing system available on current generation instruments will dramatically improve their sensitivity. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.