Program: GS-2019B-Q-113

We have recently performed a detailed spectroscopic and photometric model atmosphere analysis of 158 white dwarfs for which precise trigonometric parallax measurements are available. Based on this analysis, we identify 15 double degenerates in the solar neighborhood, six of which were previously confirmed to be in short period systems. The remaining objects are excellent binary candidates as well. We were able to follow-up four of these targets at Gemini in 2018A/B, and identified two double-lined and one single-lined spectroscopic binary systems. We have been granted additional Gemini Fast Turnaround time in the March 2019 cycle to follow-up the two binary systems visible in the spring. Here we request Gemini South time to sample the velocity curve of WD0311-649, the only fall target in the sample, over multiple nights to constrain its orbital period, component masses, and gravitational wave merger time. This program will enable us to complete and publish the results from our Gemini 2018A/B programs.