Xinglong 2.16-m Telescope Spectroscopic Classification of SN 2018hmx as a Type IIP Supernova
ATel #12152; Hanna Sai, Xiaofeng Wang, Han Lin, Xinghan Zhang, Danfeng Xiang, Liming Rui (Tsinghua University), Jie Zheng, Tianmeng Zhang (NAOC), Jujia Zhang (YNAO)
on 1 Nov 2018; 11:57 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Xiaofeng Wang (wang_xf@mail.tsinghua.edu.cn)
Subjects: Optical, Supernovae, Transient
We obtained an optical spectrum (range 390-860 nm) of SN 2018hmx (=ATLAS18xos), discovered by ATLAS, on UT October 30.8 2018 with the Xinglong 2.16-m telescope (+BFOSC) of National Astronomical Observatories of China (NAOC). The spectrum is consistent with a type IIP supernova at a few days before maximum. Cross correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, ApJ, 666, 1024) shows that it matched SN 1999em at about t=-4 days before the maximum light. After correcting for a redshift of 0.037 for its host galaxy SDSS J083337.65+553532.1, an expansion velocity of about 17000 km/s can be derived from the absorption minium of Ha line, which is unusually high for a SN IIP at this phase.
