Changing-look AGN 1ES~1927+654: Optical, UV and X-ray monitoring, capturing the unprecedented soft X-ray outburst

1ES 1927+654 is one of the most enigmatic changing-look AGN which exhibited a major TDE-like outburst in the optical/UV in Dec 2017 followed by a vanishing X-ray corona in Aug-Oct 2018. The source returned to its normal pre-flare state by March 2021. Over the last several months (since late 2022) the source has shown a rise in the soft X-ray flux which as of December 2023 has reached 7 times the pre-flare value, while there is no change in the UV flux (<30%) and very minor fluctuations in the hard X-ray 2-10 keV flux. In conjunction with the soft X-ray flare, from Feb-Dec 2023 the 5GHz core (<1pc) radio flux of the source sharply increased by a factor of 35 times, from 2 mJy to ~ 70 mJy, a unique event of a radio-quiet source becoming radio-loud in a matter of a few months. Here we report on the latest spectral and spectral-timing results using high cadence optical, UV and X-ray observations from ground based observatories and Swift, NICER, NuSTAR and XMM-Newton. (See poster submission #331 for more details of recent radio monitoring.)