Takashi Nagao Title: Observational diversity in interacting supernovae and diversity in their circumstellar material

Thursday 24 Oct 2024, 13:15 → 14:00 Europe/Stockholm

Recent observations have revealed the presence of a substantial amount of circumstellar material (CSM) in various types of supernovae (SNe), which suggests the occurrence of some unknown extensive mass ejections just before the explosions. Different observational properties of such interacting SNe should originate from different properties of their SN ejecta and CSM. It is important to clarify the properties of their SN ejecta and CSM for each type of interacting SNe, in order to understand their progenitors and mass-loss mechanisms. In this talk, I present the photometric, spectroscopic and polarimetric observations of the bright long-lived Type II SN 2021irp, and demonstrate that this SN is powered by interaction with disk-shape CSM. By comparing the observational properties with the Type Ia-CSM SN 2020uem, which is also powered by interaction with similar disk-shape CSM, I clarify the role of the SN ejecta properties in the observational properties of interacting SNe. At the same time, I discuss possible relations of SN2021irp with other interacting SNe. I also present observations of 21irp-like SNe, and discuss the diversity in their CSM, as well as their possible progenitors and mass-loss mechanisms.