Two Years of Discoveries From the All-Sky Automated Survey for SuperNovae

Thomas Holoien, Ohio State University

Even in the modern era, only human eyes scan the entire optical sky for the violent, variable and transient events that shape our universe. The All-Sky Automated Survey for Supernovae (ASAS-SN or "Assassin") is changing this by monitoring the extra-galactic sky down to V~17 mag every 2-3 days using multiple telescopes, hosted by the Las Cumbres Observatory Global Telescope Network, in the northern and southern hemispheres. Our automated pipeline schedules observations, processes data and scans images for new potential candidates without human interaction, requiring sophisticated algorithms to avoid false positive detections. Having been in operation for two years, ASAS-SN is now generating new transient discoveries daily, and has discovered over 400 new cataclysmic variable stars, over 170 new supernovae, and two tidal disruption events, including the closest ever discovered at optical wavelengths. ASAS-SN is finding nearby transients that would not be found by any other professional or amateur survey and the nearby nature of ASAS-SN discoveries allows for detailed follow-up across a wide wavelength coverage. Here we present details on the ASAS-SN survey and its data processing pipeline as well as information on discoveries made by ASAS-SN in its first two years of operation.

Abstract Author(s): Thomas W.-S. Holoien and The ASAS-SN Team