TY - GEN A1 - Finch, Nicolle L. A1 - Braker, I. P. A1 - Reindl, Nicole A1 - Barstow, Martin A. A1 - Casewell, Sarah L. A1 - Burleigh, M. A1 - Kupfer, Thomas A1 - Kilkenny, D. A1 - Geier, Stephan Alfred A1 - Schaffenroth, Veronika A1 - Bertolami Miller, Marcelo Miguel A1 - Taubenberger, Stefan A1 - Freudenthal, Joseph T1 - Spectral Analysis of Binary Pre-white Dwarf Systems T2 - Radiative signatures from the cosmos N2 - Short period double degenerate white dwarf (WD) binaries with periods of less than similar to 1 day are considered to be one of the likely progenitors of type Ia supernovae. These binaries have undergone a period of common envelope evolution. If the core ignites helium before the envelope is ejected, then a hot subdwarf remains prior to contracting into a WD. Here we present a comparison of two very rare systems that contain two hot subdwarfs in short period orbits. We provide a quantitative spectroscopic analysis of the systems using synthetic spectra from state-of-the-art non-LTE models to constrain the atmospheric parameters of the stars. We also use these models to determine the radial velocities, and thus calculate dynamical masses for the stars in each system. Y1 - 2019 SN - 978-1-58381-925-8 SN - 1050-3390 VL - 519 SP - 231 EP - 238 PB - Astronomical soc pacific CY - San Fransisco ER -