Spectroscopic Classification of SN 2018bq (=ASASSN-18ac) as a Type Ia Supernova

ATel #11154; Han Lin, Danfeng Xiang, Liming Rui, Xiaofeng Wang (Tsinghua University), Feng Xiao, Juanjuan Ren, Tianmeng Zhang (NAOC), and Jujia Zhang (YNAO)
on 10 Jan 2018; 14:26 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 510-860 nm) of SN 2018bq(=ASASSN-18ac), discovered by All Sky Automated Survey for Supernova(ASAS-SN), on UT 09.81 2018 with the 2.16-m telescope (+BFOSC) at Xinglong Station of National Astronomical Observatories of China (NAOC). The spectrum is consistent with that of a type Ia supernova about one week before the maximum light. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (SNID; Blondin and Tonry 2007, Ap.J., 666, 1024) shows that it matches with SN 2003kf at t=-7.1 day from the maximum light. After correcting for a redshift of 0.0256 for its host galaxy LCRS B110329.3-121524, an expansion velocity of about 12800 km/s can be derived from the absorption minimum of Si II 635.5 nm line. Our classification spectrum is also posted on the IAU Transient Name Sever: https://wis-tns.weizmann.ac.il/object/2018bq