2019ApJ...877...20W

SN 2007D is a nearby (redshift z = 0.023146), luminous Type Ic supernova (SN) having a narrow light curve (LC) and high peak luminosity. Previous research based on the assumption that it was powered by the ⁵⁶Ni cascade decay suggested that the inferred ⁵⁶Ni mass and the ejecta mass are ∼1.5 M_☉ and ∼3.5 M_☉, respectively. In this paper, we employ some multiband LC models to model the R-band LC and the color (V - R) evolution of SN 2007D to investigate the possible energy sources powering them. We find that the pure ⁵⁶Ni model is disfavored; the multiband LCs of SN 2007D can be reproduced by a magnetar whose initial rotational period P₀ and magnetic field strength B_p are 7.28_–0.21^+0.21 (or 9.00_–0.42^+0.32) ms and 3.10_–0.35^+0.36×10¹⁴ (or 2.81_–0.44^+0.43×10¹⁴) G, respectively. By comparing the spectrum of SN 2007D with that of some superluminous SNe (SLSNe), we find that it might be a luminous SN like several luminous "gap-filler" optical transients that bridge ordinary and SLSNe, rather than a genuine SLSN.