2025RAA....25e5022W

In this paper, we determine the photosphere evolution of PTF11rka which is a type Ic supernova (SN) by fitting its spectral energy distributions at different epochs. We find that the photosphere of PTF11rka expanded at a constant velocity at early epochs, and the photosphere temperature increased slightly after reaching a minimum. These features are reminiscent of those of SN 2017dio. Based on the photosphere module that can describe the photosphere evolution of PTF11rka, we use the ⁵⁶Ni cascade decay model to fit its multiband light curves (LCs), finding that the model can well fit the photometric data. The derived ejecta mass and ⁵⁶Ni mass are respectively 8.76 M_⊙and 0.29-0.41 M_⊙; the derived peak luminosity and the rise time of the theoretical bolometric LC of PTF11rka are ∼8.24 × 10⁴² erg s^–1 and ∼ 35 days, respectively. Moreover, we find that the theoretical multiband LCs and the theoretical bolometric LC of PTF11rka do not show early-time excesses proposed in the literature. This indicates that additional energy sources (e.g., the interaction between the ejecta and the circumstellar material) suggested to be responsible for the early-time excess can be neglected.