The broad-line type Ic SN 2020bvc: signatures of an off-axis gamma-ray burst afterglow

Understand

Long-duration gamma-ray bursts (GRBs) are almost unequivocally associated with very energetic, broad-lined supernovae (SNe) of Type Ic-BL.

• While the gamma-ray emission is emitted in narrow jets, the SN emits radiation isotropically.
• Therefore, some SN Ic-BL not associated with GRBs have been hypothesized to arise from events with inner engines such as off-axis GRBs or choked jets.
• Here we present observations of the nearby ($d = 120$ Mpc) SN 2020bvc (ASAS-SN 20bs) which support this scenario.