J. Johansson, D. A. Perley, A. Goobar, J. Wise, Yu-Jing Qin, Zoë McGrath, S. Schulze, Cameron Lemon, Anjasha Gangopadhyay, K. Tsalapatas, Igor Andreoni, Eric C. Bellm, J. S. Bloom, Richard Dekany, Suhail Dhawan, Claes Fransson, C. Fremling, M. J. Graham, Steven L. Groom, D. Gruen, Xander J. Hall, G. Hélou, M. M. Kasliwal, Russ R. Laher, R. Lunnan, A. Mahabal, Adam A. Miller, Edvard Mörtsell, J. Nordin, Jacob Osman Hjortlund, R. Michael Rich, Reed Riddle, Avinash Singh, J. Sollerman, Alice Townsend, Lin Yan
Abstract We present the discovery of SN 2025wny (ZTF25abnjznp/GOTO25gqt) and spectroscopic classification of this event as the first gravitationally lensed Type I superluminous supernova (SLSN-I). Deep ground-based follow-up observations resolve four images of the supernova with ∼ 1 . ″ 7 angular separation from the main lens galaxy, each coincident with the lensed images of a background galaxy seen in archival imaging of the field. Spectroscopy of the brightest image shows narrow features matching absorption lines at a redshift of z = 2.010 and broad features matching those seen in superluminous SNe with far-UV coverage. We infer a magnification factor of μ ∼ 20–50 for the brightest image in the system, based on photometric and spectroscopic comparisons to other SLSNe-I. SN 2025wny demonstrates that gravitationally lensed SNe are in reach of ground-based facilities out to redshifts far higher than previously assumed, and provide a unique window into studying distant supernovae and the internal properties of dwarf galaxies, as well as for time-delay cosmography.