Program: GS-2018A-Q-122

There are currently eight confirmed neutron star - M giant binary systems. The existence of these systems would seem unlikely since neutron stars are typically seen as the result of massive core collapse SNe (CCS). A CCS would blow apart a binary system with a low mass companion. No doubt these binaries evolved along different routes, perhaps involving a common envelope phase. We will use high resolution near-IR spectroscopy to measure the velocities of seven of these systems, set limits on the orbital periods, and measure CNO, alpha, Fe peak, and s/r process elemental abundances. Using these parameters we will determine the initial conditions for the binaries and probe the evolutionary history.