WINTER: a new near-IR survey telescope

The Wide-Field Infrared Transient Explorer (WINTER) is a new time-domain instrument which will perform a seeing-limited survey of the near-infrared sky. I will present the design and science goals of the WINTER instrument, which will be deployed on a dedicated 1-meter robotic telescope at Palomar Observatory. Among the many near-infrared targets of interest, WINTER is principally designed for follow-up of kilonovae from binary neutron star and neutron star-black hole mergers detected in gravitational waves. WINTER will be sensitive to kilonovae with 90% localization areas smaller than 150 (450) square degrees out to a distance of 350 (200) Mpc. In addition to kilonova follow-up, WINTER will conduct a wide range of time-domain surveys to a depth of J=21 magnitudes, building up a deep co-added image of the near-infrared sky and studying near-infrared transients including supernovae, tidal disruption events, and transiting exoplanets around low mass stars. WINTER’s custom camera combines six commercial large-format Indium Gallium Arsenide (InGaAs) sensors, observing in Y, J, and a short-H (Hs) band filters (0.9-1.7 microns), and employs a novel tiled optical design to cover a >1 degree squared field of view with 90% fill factor. I will include updates on the final integration of the WINTER instrument and commissioning at Palomar Observatory.