Follow-up of SN 2025wny I: Space-based Observations of the First Multiply-imaged Superluminous Supernova
Year: 2026
Type: preprint
Abstract: We present space-based follow-up observations of the superluminous Type I supernova (SLSN-I) SN 2025wny at redshift $z_{SN}=2.0151$, gravitationally lensed by two galaxies at redshifts $z_{G1}=0.3755$ and $z_{G2}=0.3766$ into five resolved images. SN 2025wny is the first strongly lensed SLSN discovered and the first galaxy-scale lensed supernova for which both photometric and spectroscopic time-delay measurements are feasible. As such, it opens a new observational window for precision cosmology and the study of stellar explosions near the epoch of peak cosmic star formation. Our follow-up observations comprise two epochs of Hubble Space Telescope (HST) imaging, together with near-infrared imaging and spectroscopy obtained with the James Webb Space Telescope (JWST). From these data, we measure precise astrometry and multi-band photometry for the five resolved supernova images, the host galaxy, and the two deflecting galaxies. HST provides accurate relative image positions and rest-frame ultraviolet photometry, while JWST delivers complementary near-infrared imaging and spectroscopy probing the rest-frame optical at high signal-to-noise ratio. Together they yield a detailed characterization of both the lensing configuration and the supernova spectral energy distribution over a broad wavelength range. The data presented here provide the observational foundation for the accompanying analyses of the supernova properties, lens modeling, and time-delay cosmography, including the astrometric, photometric, and spectroscopic information required to measure $H_0$.
Source: arXiv (Cornell University)
Authors: Goobar, Ariel, Johansson, Joel, Mörtsell, Edvard, Lemon, Cameron, Schulze, Steve, Dhawan, Suhail, Townsend, Alice, Li, Maggie L., Qin, Yu-Jing, Yan, Lin, Fremling, Christoffer, Kasliwal, Mansi M., Nugent, Peter, Smith, Graham P., Sollerman, Jesper, Andreoni, Igor, Arendse, Nikki, Collett, Thomas E., Nordin, Jakob, Hjortlund, Jacob Osman, Perley, Daniel A., Rigault, Mickael, Thorp, Stephen, Wise, Jacob L.
Institutions: Stockholm University, Weizmann Institute of Science, California Institute of Technology, Lawrence Berkeley National Laboratory, University of California, Berkeley, University of Birmingham, University of North Carolina at Chapel Hill, University of Nova Gorica, University of Portsmouth, Humboldt-Universität zu Berlin, Liverpool John Moores University, Institute of Astronomy
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: U.S. Department of Energy, National Aeronautics and Space Administration, Government of the United Kingdom, UK Research and Innovation, National Energy Research Scientific Computing Center, European Commission, Swedish National Space Agency, Vetenskapsrådet, HORIZON EUROPE Framework Programme, Science and Technology Facilities Council, HORIZON EUROPE Marie Sklodowska-Curie Actions
Awards: EDUCATE: Excellence Dark Universe Centre and Technology Enabler, Charting new physics with time-domain astronomy, G2380187409, G5077163979, Gravitationally Lensed Supernovae, Hubble trouble: A new measure of the universal expansion using lensed supernovae, GREAT: Gravitational Radiation and Electromagnetic Astrophysical Transients, Machine learning for Sciences and Humanities, G814503682, The Enigma of Dark Energy: what is it?, UK involvement in LSST: Phase C (University of Birmingham component)
OpenAlex ID: W7204805079