Close, bright, and boxy: the superluminous SN 2018hti. Issue 3 (17th March 2022)

• Record Type: Journal Article
• Authors: Fiore, A; Benetti, S; Nicholl, M; Reguitti, A; Cappellaro, E; Campana, S; Bose, S; Paraskeva, E; Berger, E; Bravo, T M; Burke, J; Cai, Y-Z; Chen, T-W; Chen, P; Ciolfi, R; Dong, S; Gomez, S; Gromadzki, M; Gutiérrez, C P; Hiramatsu, D; Hosseinzadeh, G; Howell, D A; Jerkstrand, A; Kankare, E; Kozyreva, A; Maguire, K; McCully, C; Ochner, P; Pellegrino, C; Pignata, G; Post, R S; Elias-Rosa, N; Shahbandeh, M; Schuldt, S; Thomas, B P; Tomasella, L; Vinkó, J; Vogl, C; Wheeler, J C; Young, D R;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 512:Issue 3(2022)
• Page Start: 4484
• Page End: 4502
• Publication Date: 2022-03-17
• Subjects: supernovae: general -- supernovae: individual: SN 2018hti; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac744
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: SN 2018hti was a very nearby ( z = 0.0614) superluminous supernova with an exceedingly bright absolute magnitude of −21.7 mag in r band at maximum. The densely sampled pre-maximum light curves of SN 2018hti show a slow luminosity evolution and constrain the rise time to ∼50 rest-frame d. We fitted synthetic light curves to the photometry to infer the physical parameters of the explosion of SN 2018hti for both the magnetar and the CSM-interaction scenarios. We conclude that one of two mechanisms could be powering the luminosity of SN 2018hti; interaction with ∼10 M⊙ of circumstellar material or a magnetar with a magnetic field of B p ∼ 1.3 × 10 13 G, and initial period of P spin ∼ 1.8 ms. From the nebular spectrum modelling we infer that SN 2018hti likely results from the explosion of a ${\sim}40\, \mathrm{M}_\odot$ progenitor star.