A motion-based search of the outer solar system and beyond with WISE and NEOWISE

NASA's WISE satellite has opened up the infrared sky, mapping the cosmos at 3-5 microns over a period of more than eight years. We use time-resolved, coadded W2-band images from WISE, and the follow-on NEOWISE mission to explore an approximately 40x40 square-degree area of the sky. The coadds allow us to probe to a W2-band magnitude around 16 Vega, significantly fainter than in previous work, while retaining the long time baseline needed for motion detection of faint sources. Here we report the (re)discovery of cold brown dwarfs with proper motion above 2 arcseconds per year, and the results of a preliminary search for 'Planet Nine', a hypothesized giant planet in the outer regions of the solar system.