Closest Ultrastripped Supernova Found: SN 2021agco in UGC 3855

Astronomers have discovered a new ultrastripped supernova, SN 2021agco, in the galaxy UGC 3855. The supernova was detected using the Half Meter Telescope (HMT) and is classified as an ultrastripped SN Ib, the closest of its subtype to Earth. The progenitor of SN 2021agco experienced violent mass loss, with most of its outer layer stripped before the explosion. The observations also revealed information about the host galaxy, UGC 3855, including its age, mass, and star-formation rate.