Reguitti, AndreaPastorello, A.Pignata, G.Benetti, S.Cappellaro, E.Turatto, M.Agliozzo, C.Bufano, F.Morrell, N. I.Olivares E., F.Reichart, D. E.Haislip, J. B.Kouprianov, V.Smartt, S. J.Ciroi, S.2023-04-172023-04-172019-01Monthly Notices of the Royal Astronomical Society Volume 482, Issue 2, Pages 2750 - 2769 January 20190035-8711https://repositorio.unab.cl/xmlui/handle/ria/48627Indexación ScopusWe present photometric and spectroscopic analysis of the peculiar core-collapse supernova (SN) 2013gc, spanning 7 yr of observations. The light curve shows an early maximum followed by a fast decline and a phase of almost constant luminosity. At +200 d from maximum, a brightening of 1 mag is observed in all bands, followed by a steep linear luminosity decline after +300 d. In archival images taken between 1.5 and 2.5 yr before the explosion, a weak source is visible at the supernova location, with mag ≈20. The early supernova spectra show Balmer lines, with a narrow (∼560 km s-1) P-Cygni absorption superimposed on a broad (∼3400 km s-1) component, typical of Type IIn events. Through a comparison of colour curves, absolute light curves, and spectra of SN 2013gc with a sample of supernovae IIn, we conclude that SN 2013gc is a member of the so-called Type IId subgroup. The complex profile of the Hα line suggests a composite circumstellar medium geometry, with a combination of lower velocity, spherically symmetric gas, and a more rapidly expanding bilobed feature. This circumstellar medium distribution has been likely formed through major mass-loss events that we directly observed from 3 yr before the explosion. The modest luminosity (MI ∼-16.5 near maximum) of SN 2013gc at all phases, the very small amount of ejected 56Ni (of the order of 10-3 M⊙), the major pre-supernova stellar activity, and the lack of prominent [O I] lines in the late-time spectra support a fall-back core-collapse scenario for the massive progenitor of SN 2013gc.enSupernovae: generalSupernovae: individual: SN2013gcSN1994ajSN1996alSN1996LSN2000PArtículoAttribution 4.0 International (CC BY 4.0)10.1093/mnras/sty2870