# TESS Program G08006

Title: Integrating TESS Light Curves And Neid Orbit Solutions To Define Angular Momentum Evolution In Interacting Binary Stars

PI: Mathieu, Robert - University Of Wisconsin-Madison

Type: SMALL

Summary: Close binary stars launch many astrophysical phenomena of current interest. A crucial unknown in binary evolution is the evolution of angular momentum. We propose an integrated study of spin and orbit angular momentum in late-type main sequence white dwarf (MS-WD) binaries to simultaneously determine angular momentum evolution of the accretor, energy and angular momentum evolution of the binary orbit, stability domains and tidal evolution. We have identified 97 MS-WD binaries with periodic TESS light curves. The morphologies indicate rotational or ellipsoidal variability. Our ground-based focus will obtain spectroscopic orbit solutions using WIYN/NEID radial-velocity measurements. Analysis and modeling will include joint distributions of spins and orbits and case studies with WD masses.