Spectroscopic Classification of ASASSN-15ug and ASASSN-15ul
ATel #8543; E. Falco, P. Berlind, P. Challis, R. Kirshner (Harvard-Smithsonian CfA), J. L. Prieto (Diego Portales; MAS)
on 14 Jan 2016; 18:50 UT
Credential Certification: Jose L. Prieto (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
We obtained an optical spectra (range 350-760 nm) of ASASSN-15ug (ATel #8436, #8439) and ASASSN-15ul (ATel #8463) on UT 2016 Jan 11 with the F. L. Whipple Observatory 1.5-m telescope (+ FAST). Cross-correlation with a library of supernova spectra using SNID (Blondin & Tonry 2007, ApJ, 666, 1024) shows that ASASSN-15ug is a Type II a few days after peak (best fit template is the Type II-P SN 2004et) and ASASSN-15ul is a Type Ia SN (best fit templates are SN 1991bg-like; the spectrum has strong host-galaxy contamination) about 1-2 weeks after peak. We detect a faint narrow emission feature in the spectrum of ASASSN-15ug at 6708.6 Angstroms consistent with host galaxy H-alpha at redshift z=0.0222. After correcting the spectrum of ASASSN-15ug for this host redshift, we measure the minimum of the H-beta P-Cygni absorption at -9300 km/s (the H-alpha P-Cygni absorption is very weak/absent).