SN 2019qem: decades of extreme mass loss before the explosion of a luminous, long-lived Type IIn supernova

Joysankar Majumdar, Mariusz Gromadzki, Takashi J. Moriya +43

We present the luminous, long-lived Type IIn SN 2019qem and use it to reconstruct how much mass its progenitor lost and when. We combine host-subtracted optical and mid-infrared ph…