Galactic LISA sources and their potential for multi-messenger and multi-wavelength studies

The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave (GW) detector sensitive at lower frequencies than LIGO. The dominant Galactic sources in the LISA band will be binary stars with orbital periods <60min, so called ultracompact binaries (UCB). They are a rare and exotic class of binary stars with orbital periods as short as a few minutes and physical separations between components of the order of the Earth-Moon distance. Theoretical studies predict that LISA will detect a few thousand Galactic binaries after one year of operations which are also bright in the electromagnetic wavebands. This will allow us to perform combined GW and electromagnetic multi-messenger studies ona statistical sample of UCBs and derive population properties of these systems with unprecedented quality. Currently, only about a dozen of these LISA guaranteed sources have been studied in the electromagnetic wavebands. In this talk I will give an overview of the known population of LISA guaranteed sources and outline some opportunities for upcoming multi-messenger observations. I will also discuss the potential of LISA detections of stellar-mass binary black holes  about one year prior to their merger where the coalescence can be detected with LIGO. These pre-merger detections in the LISA frequency band open-up unique opportunities such pre-pointing of telescopes to perform coincident GW and multi-wavelength electromagnetic observations of binary black hole coalescences.