Dastidar, RayaRayaDastidarMisra, KuntalKuntalMisraHosseinzadeh, G.G.HosseinzadehPASTORELLO, AndreaAndreaPASTORELLOPumo, M. L.M. L.PumoValenti, S.S.ValentiMcCully, C.C.McCullyTOMASELLA, LinaLinaTOMASELLAArcavi, I.I.ArcaviELIAS DE LA ROSA, NANCY DEL CARMENNANCY DEL CARMENELIAS DE LA ROSASingh, MridweekaMridweekaSinghGangopadhyay, AnjashaAnjashaGangopadhyayHowell, D. A.D. A.HowellMorales-Garoffolo, AntoniaAntoniaMorales-GaroffoloZAMPIERI, LucaLucaZAMPIERIKumar, BrijeshBrijeshKumarTURATTO, MassimoMassimoTURATTOBENETTI, StefanoStefanoBENETTITARTAGLIA, LeonardoLeonardoTARTAGLIAOchner, P.P.OchnerSahu, D. K.D. K.SahuAnupama, G. C.G. C.AnupamaPandey, S. B.S. B.Pandey2020-09-292020-09-2920180035-8711http://hdl.handle.net/20.500.12386/27512We present optical photometry and spectroscopy from about a week after explosion to ∼272 d of an atypical Type IIP supernova, SN 2015ba, which exploded in the edge-on galaxy IC 1029. SN 2015ba is a luminous event with an absolute V-band magnitude of -17.1 ± 0.2 mag at 50 d since explosion and has a long plateau lasting for ∼123 d. The distance to the SN is estimated to be 34.8 ± 0.7 Mpc using the expanding photosphere and standard candle methods. High-velocity H Balmer components constant with time are observed in the late-plateau phase spectra of SN 2015ba, which suggests a possible role of circumstellar interaction at these phases. Both hydrodynamical and analytical modelling suggest a massive progenitor of SN 2015ba with a pre-explosion mass of 24-26 M<SUB>☉</SUB>. However, the nebular spectra of SN 2015ba exhibit insignificant levels of oxygen, which is otherwise expected from a massive progenitor. This might be suggestive of the non-monotonical link between O-core masses and the zero-age main sequence mass of pre-supernova stars and/or uncertainties in the mixing scenario in the ejecta of supernovae.STAMPAenArticle10.1093/mnras/sty16342-s2.0-85055346772000441380100069https://academic.oup.com/mnras/article/479/2/2421/50422872018MNRAS.479.2421DFIS/05 - ASTRONOMIA E ASTROFISICA