PASTORELLO, AndreaAndreaPASTORELLOTURATTO, MassimoMassimoTURATTOBENETTI, StefanoStefanoBENETTICAPPELLARO, EnricoEnricoCAPPELLARODanziger, I. J.I. J.DanzigerMazzali, P. A.P. A.MazzaliPatat, F.F.PatatFilippenko, A. V.A. V.FilippenkoSchlegel, D. J.D. J.SchlegelMatheson, T.T.Matheson2023-01-162023-01-1620020035-8711http://hdl.handle.net/20.500.12386/32861We present the photometric and spectroscopic evolution of the type IIn SN 1995G in NGC 1643, on the basis of 4 years of optical and infrared observations. This supernova shows very flat optical light curves similar to SN 1988Z, with a slow decline rate at all times. The spectra are characterized by strong Balmer lines with multiple components in emission and with a P Cygni absorption component blueshifted by only 700kms<SUP>-1</SUP>. This feature indicates the presence of a slowly expanding shell above the SN ejecta as in the case of SNe 1994aj and 1996L. As in other SNe IIn, the slow luminosity decline cannot be explained only with a radioactive energy input, and an additional source of energy is required, most likely that produced by the interaction between supernova ejecta and a pre-existent circumstellar medium (CSM). It was estimated that the shell material has a density n<SUB>H</SUB>>>10<SUP>8</SUP>cm<SUP>-3</SUP>, consistent with the absence of forbidden lines in the spectra. About 2 years after the burst the low-velocity shell is largely overtaken by the SN ejecta and the luminosity drops at a faster rate.STAMPAenArticle10.1046/j.1365-8711.2002.05366.x2-s2.0-19044372575https://academic.oup.com/mnras/article/333/1/27/1187467https://api.elsevier.com/content/abstract/scopus_id/19044372575https://ui.adsabs.harvard.edu/abs/2002MNRAS.333...27P/abstract2002MNRAS.333...27PFIS/05 - ASTRONOMIA E ASTROFISICA