Spectroscopic Classification of ASASSN-18tn (SN 2018fpb) as a young type IIb Supernova
ATel #12010; Jujia Zhang, Xiliang Zhang (YNAO) ; Xiaofeng Wang, Saihanna (Tsinghua University)
on 5 Sep 2018; 11:09 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Ju-Jia Zhang (jujia@ynao.ac.cn)
Subjects: Optical, Supernovae
Referred to by ATel #: 12051
We obtained an optical spectrum (range 350-890 nm) of ASASSN-18tn/AT 2018fpb on UT Sep. 4.7 2018 with the Lijiang 2.4 m telescope (LJT+YFOSC) at Lijiang Observatory of Yunnan Observatories (YNAO). The spectrum is consistent with a type IIb supernova at a few days before the maximum light. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, ApJ, 666, 1024) shows that it matches with SN 1993J at t = -5 days from the maximum light. We noted that the redshift inferred from the narrow H alpha emission presented in the SN spectrum is about 0.0166, which is slightly larger than the estimation of the host galaxy KUG 2357+340 reported in NED (i.e., 0.0148). This difference might indicate an apparently large velocity distribution of the stars within the host galaxy.