Spectroscopic classification of ASASSN-17is (=AT 2017fbu) as a Type II Supernova

ATel #10580; Osmar Rodriguez (UNAB/MAS), J. L. Prieto (UDP/MAS)
on 17 Jul 2017; 20:44 UT
Credential Certification: Jose L. Prieto (jose.prietok@mail.udp.cl)

Subjects: Optical, Supernovae, Transient

We obtained an optical spectrum (450-760nm) of ASASSN-17is/AT2017fbu (ATel #10555) on 2017 July 15.41 UT with GMOS, mounted on Gemini-South. Using the SNID code (Blondin & Tonry, 2007, ApJ, 666, 1024) we find a good match with a Type II supernova at z=0.011, consistent with the redshift of its host galaxy IC 211. From the H-alpha absorption minimum we estimate an expansion velocity of about 10200 km/s.