Orateur
Description
Strongly lensed supernovae (SNe) enable independent measurements of the Hubble constant (H₀) through time-delay cosmography, offering a critical test of the current H₀ tension. Their rapid follow-up also enables unique diagnostics of early explosion physics and progenitor properties. In this talk, I will present forecasts for (a) measurements of the Hubble constant and (b) constraints on SN progenitors achievable with forthcoming samples of strongly lensed SNe from Rubin-LSST. I will then describe our newly developed deep-learning approaches to search for lensed SNe in LSST with minimal contamination rates, including flexible architectures designed to classify multi-band image time series of variable length.
As a pathfinder, I will present the analysis and modeling of SN 2025wny (SN Winny) at zₛ = 2.008, the first confirmed galaxy-scale strongly lensed superluminous SN detected with ZTF in mid-2025. Spectroscopic follow-up of SN Winny reveals a blue continuum and weak UV features consistent with a hot Type I SLSN. Moreover, its long time delays make SN Winny well suited for independent measurements of the Hubble constant. I will present the follow-up campaign, characterization, and modeling of this exciting system and show how it paves the way for future analyses of larger samples selected by Rubin-LSST.