16217

Double white dwarf binaries (aka AM CVns) are systems with orbital periods virgul5-65 mins. Because of their short orbits comma they are important sources of low-frequency gravitational waves. They are also candidates for progenitors of SN Ia through the double degenerate path. In globular clusters (GCs) they are predicted to exist in large amounts due to stellar interactions. However comma no single AM CVn has yet been confirmed in any GC. We propose to carry out the first multi-epoch UV study of the low extinction comma relatively massive Galactic GC 47 Tuc to identify the missing population of AM CVns through their outbursts. Using this novel technique we will test dynamical formation and evolutionary models of these binaries in clusters. We will also refine predictions of AM CVns as potential gravitational wave sources to be detected with LISA. Finding an upper limit on the rate of identifications that is lower than expected would change the current paradigm of GCs as efficient factories of compact binaries comma especially those harboring white dwarfs. That would mean that the double degenerate path for SN Ia is negligible comma which ultimately has cosmological implications.