DES16C3cje: A low-luminosity, long-lived supernova Gutiérrez, C. P. Galbany González, Lluis Supernovae: general Supernovae: individual (DES16C3cje) We present DES16C3cje, a low-luminosity, long-lived type II supernova (SN II) at redshift 0.0618, detected by the Dark Energy Survey (DES). DES16C3cje is a unique SN. The spectra are characterized by extremely narrow photospheric lines corresponding to very low expansion velocities of . 1500 km s−1 , and the light curve shows an initial peak that fades after 50 days before slowly rebrightening over a further 100 days to reach an absolute brightness of M푟 ∼ −15.5 mag. The decline rate of the late-time light curve is then slower than that expected from the powering by radioactive decay of 56Co, but is comparable to that expected from accretion power. Comparing the bolometric light curve with hydrodynamical models, we find that DES16C3cje can be explained by either i) a low explosion energy (0.11 foe) and relatively large 56Ni production of 0.075 M from a ∼ 15 M red supergiant progenitor typical of other SNe II, or ii) a relatively compact ∼ 40 M star, explosion energy of 1 foe, and 0.08 M of 56Ni. Both scenarios require additional energy input to explain the late-time light curve, which is consistent with fallback accretion at a rate of ∼ 0.5 × 10−8 M s−1. 2020-10-05T12:50:08Z 2020-10-05T12:50:08Z 2020-07 journal article Gutiérrez, C. P., Sullivan, M., Martinez, L., Bersten, M. C., Inserra, C., Smith, M., ... & Nugent, P. (2020). DES16C3cje: A low-luminosity, long-lived supernova. Monthly Notices of the Royal Astronomical Society. [DOI: 10.1093/mnras/staa1452] http://hdl.handle.net/10481/63667 10.1093/mnras/staa1452 eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España OXFORD UNIV PRESS