C Humina, C. P. Gutiérrez, H. Kuncarayakti, T. Nagao, S. González-Gaitán, T Kangas, T Kravtsov, K Maeda, S. Mattila, T. M. Reynolds, L Tartaglia, S Benetti, M. Fraser, C Gall, P Lundqvist, A. Morales-Garoffolo, M. Stritzinger
Abstract
The discovery of stripped-envelope core-collapse supernovae (SNe) interacting with dense circumstellar medium (CSM) challenges our current understanding of massive star evolution. We present late-time observations of the interacting Type Ic SN 2017dio and investigate its mass-loss mechanism and progenitor channel. We analysed late-time spectra and light curves that are dominated by a strong ejecta─CSM interaction and reveal a slow photometric evolution primarily powered by this interaction. We examined the CSM and the source of the infrared (IR) excess by modelling the radiation produced by the ejecta─CSM interaction and the IR echo from circumstellar dust. In addition, we studied the temporal evolution of spectral features, with a particular emphasis on the Hα emission line. From the combined analysis of the light curves and spectral properties, we infer that the peak mass-loss rate for the CSM reaches ∼0.2 M⊙ yr−1 and that the typical value over most epochs is ∼0.06 M⊙ yr−1. The nearby CSM was formed over a period of 4 to 65 years before the explosion. The CSM radius begins at ∼1.3 × 1015 cm. The IR excess identified in the light curves is consistent with the radiation from dust with a mass increasing from ∼0.001 to ∼0.005 M⊙ in the case of carbon dust or ∼0.005 to ∼0.02 M⊙ in the case of silicate dust. From IR echo modelling, we estimate an upper limit on the dust mass of 4 × 10−5 M⊙, which implies an SN progenitor mass-loss rate of 2.4 × 10−5 M⊙ yr−1 at the dust evaporation radius determined by the SN peak luminosity (0.017 pc for carbon dust, corresponding to mass loss ∼170 years before the explosion). This implies a very rapid increase in the mass-loss rate ahead of the explosion. Although the progenitor of SN 2017dio has lost its helium envelope, it interacted with a hydrogen-rich CSM formed shortly before the explosion, strongly suggesting that this material originated from a companion star rather than the progenitor itself.
Keywords
stars: massive / stars: mass-loss / supernovae: general / supernovae: individual: SN 2017dio
Astronomy & Astrophysics
Volume 712, Article Number A144, Number of pages 18
2026 August
