Abstract

Many astronomical events shine the brightest in the infrared (IR) due to atomic opacity, self enshrouding, dust extinction, or low temperature. When we saw the first electromagnetic counterpart to gravitational waves from a neutron star merger, it was the rapid reddening and IR spectral features that confirmed the synthesis of heavy elements by the r-process. Neutron star black hole mergers may shine brightest in the IR. Multi-messenger high energy neutrinos are also accompanied by tidal disruption flares with strong IR dust echoes. A classical nova (or even a Galactic supernova) deep in the disk of the Milky Way is also brightest in the IR on account of line-of-sight dust extinction. Stellar mergers, planet-star engulfments and mass-losing stars are also extremely red due to self obscuration. Yet, the IR time-domain is hitherto largely unexplored.  In this colloquium, I will describe my efforts to open up the dynamic IR sky with a series of experiments. I will begin with progress on common envelope evolution with the Spitzer SPIRITS survey and JWST spectroscopy. Next, I will present Galactic science with the first wide-field infrared surveyor, Palomar Gattini IR, which has been mapping 15000 square degrees to a J-band depth of 16 mag every two nights. Next I will describe two next generation infrared surveyors designed to probe r-process in the imminent fourth gravitational wave observing run: WINTER at Palomar Observatory and DREAMS at Siding Springs Observatory. Looking ahead, I will conclude with my plans for an IR dream machine -- Cryoscope in Antarctica.