Jacob Jencson (JHU/STScI): "Exploring Circumstellar Interaction and Dust Formation in Exotic Infrared Transients"


In its final years, the Spitzer Space Telescope expanded our view of the dynamic infrared (IR) sky by revealing entirely new and emerging classes of IR-dominated transients. All-sky monitoring by the reactivated NEOWISE mission is continuing this exploration. These transients are diverse, spanning the luminosity range from classical novae to the brightest supernovae (SNe) and including several classes of “gap” events in between. Strong IR emission is often a signature of dust in the vicinity of these events, either pre-existing in the complex circumstellar environments of their progenitor stars or newly formed in their dense outflows. In this talk, I will first discuss the remarkable case of SN 2017gkp, a unique explosion showing evidence for strong circumstellar interaction and an exceptional multi-peaked IR light curve lasting more than 1000 days in NEOWISE monitoring. Next, I will discuss new classes of IR-dominated transients that may lack any detectable optical emission whatsoever. Some of these transients are thought to be associated with the final stages of common-envelope evolution in merging binary stars that are rapidly obscured by early dust formation. The key to confirming this hypothesis is mid-IR spectroscopy, now obtainable with the successful launch of JWST. I will show the first results from a Cycle 1 JWST GTO program (PI M. Ressler) to constrain the properties of the dust in two such transients, providing vital new clues to confirm their origins.