Valerin, G.Pumo, M.L.Pastorello, A.Reguitti, A.Elias Rosa, N.Gútierrez, C.P.Kankare, E.Fraser, M.Mazzali, P.A.Howell, D.A.Kotak, R.Galbany, L.2023-11-222023-11-222022-07-01Monthly Notices of the Royal Astronomical Society, Volume 513, Issue 4, Pages 4983 - 4999, 1 July 20220035-8711https://repositorio.unab.cl/xmlui/handle/ria/54022Indexación: Scopus.Photometric and spectroscopic data for two Low Luminosity Type IIP Supernovae (LL SNe IIP) 2020cxd and 2021aai are presented. SN 2020cxd was discovered 2 d after explosion at an absolute magnitude of Mr = -14.02 ± 0.21 mag, subsequently settling on a plateau which lasts for ∼120 d. Through the luminosity of the late light curve tail, we infer a synthesized 56Ni mass of (1.8 ± 0.5) × 10-3 M⊙. During the early evolutionary phases, optical spectra show a blue continuum ($T\, \gt $8000 K) with broad Balmer lines displaying a P Cygni profile, while at later phases, Ca ii, Fe ii, Sc ii, and Ba ii lines dominate the spectra. Hydrodynamical modelling of the observables yields $R\, \simeq$ 575 R⊙ for the progenitor star, with Mej = 7.5 M⊙ and $E\, \simeq$ 0.097 foe emitted during the explosion. This low-energy event originating from a low-mass progenitor star is compatible with both the explosion of a red supergiant (RSG) star and with an Electron Capture Supernova arising from a super asymptotic giant branch star. SN 2021aai reaches a maximum luminosity of Mr = -16.57 ± 0.23 mag (correcting for AV = 1.92 mag), at the end of its remarkably long plateau (∼140 d). The estimated 56Ni mass is (1.4 ± 0.5) × 10-2 M⊙. The expansion velocities are compatible with those of other LL SNe IIP (few 103 km s-1). The physical parameters obtained through hydrodynamical modelling are $R\, \simeq$ 575 R⊙, Mej = 15.5 M⊙, and E = 0.4 foe. SN 2021aai is therefore interpreted as the explosion of an RSG, with properties that bridge the class of LL SNe IIP with standard SN IIP events. © 2022 The Author(s).enSupernovae: generalSupernovae: individual: SN 2020cxd, SN 2021aaiBarium compoundsExplosionsIron compoundsLuminanceArtículoCC BY 4.0 DEED Atribución 4.0 Internacional10.1093/mnras/stac1182