Abstract
The ultraviolet (UV) and near-infrared (NIR) photometric and optical spectroscopic observations of SN 2020acat covering ∼250 d after explosion are presented here. Using the fast rising photometric observations, spanning from the UV to NIR wavelengths, a pseudo-bolometric light curve was constructed and compared to several other well-observed Type IIb supernovae (SNe IIb). SN 2020acat displayed a very short rise time reaching a peak luminosity of Log10(L) = 42.49 ± 0.17 erg s-1 in only ∼14.6 ± 0.3 d. From modelling of the pseudo-bolometric light curve, we estimated a total mass of 56Ni synthesized by SN 2020acat of MNi = 0.13 ± 0.03 M⊙, with an ejecta mass of Mej = 2.3 ± 0.4 M⊙ and a kinetic energy of Ek = 1.2 ± 0.3 × 1051 erg. The optical spectra of SN 2020acat display hydrogen signatures well into the transitional period (≳ 100 d), between the photospheric and the nebular phases. The spectra also display a strong feature around 4900 Å that cannot be solely accounted for by the presence of the Fe ii 5018 line. We suggest that the Fe ii feature was augmented by He i 5016 and possibly by the presence of N ii 5005. From both photometric and spectroscopic analysis, we inferred that the progenitor of SN 2020acat was an intermediate-mass compact star with an MZAMS of 15-20 M⊙.
Original language | English |
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Pages (from-to) | 5540-5558 |
Number of pages | 19 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 513 |
Issue number | 4 |
DOIs | |
Publication status | Published - 5 May 2022 |
Bibliographical note
Publisher Copyright:© 2022 The Author(s).
Keywords
- supernovae: general
- supernovae: individual: SN 2020acat
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science