The Type II Superluminous SN 2008es at Late Times: Near-Infrared Excess and Circumstellar Interaction

Understand

SN 2008es is one of the rare cases of a Type II superluminous supernova (SLSN) showing no relatively narrow features in its early-time spectra, and therefore its powering mechanism is under debate between circumstellar interaction (CSI) and magnetar spin-down.

• Late-time data are required for better constraints.
• We present optical and near-infrared (NIR) photometry obtained from Gemini, Keck, and Palomar Observatories from 192 to 554 days after explosion.
• Only broad H$\alpha$ emission is detected in a Gemini spectrum at 288 days.