Evidence for Extended Hydrogen-Poor CSM in the Three-Peaked Light Curve of Stripped Envelope Ib Supernova

Understand

We present multi-band ATLAS photometry for SN 2019tsf, a stripped-envelope Type Ib supernova (SESN).

• The SN shows a triple-peaked light curve and a late (re-)brightening, making it unique among stripped-envelope systems.
• The re-brightening observations represent the latest photometric measurements of a multi-peaked Type Ib SN to date.
• As late-time photometry and spectroscopy suggest no hydrogen, the potential circumstellar material (CSM) must be H-poor.