First results from the Distant Giants survey and a sub-stellar companion orbiting HD 191939

We report the status of Distant Giants, a 3-year radial velocity (RV) survey designed to estimate the conditional occurrence of long-period Jupiter analogs in systems hosting small transiting planets. Since beginning the survey over a year ago, we have collected more than 2500 RV measurements of 47 Sun-like stars with the W. M. Keck Observatory High Resolution Echelle Spectrometer and the Automated Planet Finder (APF) at Lick Observatory. Thus far, we have detected evidence of distant companions in 10 of these systems, most of which have orbital periods significantly longer than the current observing baseline. We introduce a forward modeling technique for constraining the properties of these long-period companions using both RV and astrometric data products, and apply it to the Distant Giants target HD 191939. We find that the outer companion in this system has a mass of 2-11 Jupiter masses and a period of 6-20 years at 95% confidence. After examining this method’s performance in individual systems, we discuss its extension to the completed Distant Giants survey as well as the California Legacy Survey.