16883

SGR 1935+2154 is a notoriously active magnetar undergoing a period of high energy activity. Similar recent activity in 2020 elicited a series of Fast Radio Burst (FRB) like events from the source and triggered a breakthrough in our understanding of extragalactic FRB progenitors. FRBs are one of the key mysteries of recent astrophysics comma and SGR 1935+2154 represents our chance to study the systems that produce them in unprecedented detail. HST has already contributed significantly to this goal - a near-infrared detection of the source has been made and observed to undergo significant variability. Here we propose to capitalise on results from the most recent sighting by HST of the NIR counterpart comma which has brightened by a factor of 4 comma to probe the origin of this emission. The origin of optical and NIR emission from magnetars is poorly known. Models range from fallback of material from a disc and magnetosphere-powered emisson comma to surviving binary companions. Each has implications for the formation of magnetars and the nature of the emission is crucial to understand in order to motivate and inform future multi-wavelength follow-up of FRBs. Our proposed observations will obtain a NIR spectral energy distribution for SGR 1935+2154 comma to be readily compared with models for the emission comma in order to uncover its origin. We will also enact a cycle-long monitoring campaign to double the epochs of observations for this object comma in order to properly understand the nature of its variability comma and its correlation (or lack of) with activity at both higher and lower frequencies.