“Hunting for Hidden Explosions with SPIRITS”
Abstract: Despite the enormous progress enabled by wide-field optical transient surveys, the census of core-collapse supernovae, even in the local 40 Mpc volume, is incomplete. Infrared searches, now systematically exploring the dynamic IR sky, offer an ideal platform to discover these missing stellar explosions. I will present results from 5 years of SPIRITS, the Spitzer Infrared Intensive Transients Survey, an ongoing search of nearby galaxies for transients in the Spitzer/IRAC 3.6 and 4.5 micron imaging bands. We have now discovered a sample of 9 luminous infrared transients, of which 5 are likely heavily dust-extinguished core-collapse supernovae based on detailed characterizations in the optical, IR, and radio. Our results suggest ~40% of core-collapse supernovae are being missed in nearby galaxies. The remaining events span diverse classifications including a stellar merger, weak or electron-capture supernovae, and dust-forming, self-obscuring outbursts of massive evolved stars, suggesting that a broad array of eruptive and explosive stellar phenomena are waiting to be uncovered by new and upcoming infrared transient searches.