Spectroscopic classification of SN 2018aql as a young type IIP supernova

ATel #11525; Jujia Zhang, Yuxin Xin (YNAO); Zhijian Xu; Zhitong Li, Wenxiong Li, Xiaofeng Wang (THU) and Tianmeng Zhang (NAOC)
on 11 Apr 2018; 01:35 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Ju-Jia Zhang (jujia@ynao.ac.cn)

Subjects: Optical, Supernovae

We obtained an optical spectrum (range 350-900 nm) of SN 2018aql, discovered by the Tsinghua-NAOC Transient Survey (TNTS), on UT Apr. 09.85 2018 with the 2.4-m telescope (+YFOSC) at LiJiang Observatory of Yunnan Observatories (YNAO). The spectrum is consistent with a type IIP supernova at a few days before the maximum light, showing a blue continuum and prominent P-Cygni features of Balmer lines. 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 1999em at t = -4 days from the maximum light. After correcting for a redshift of 0.074 for its host galaxy (via SNID), an expansion velocity of about 12,000 km/s can be derived from the absorption minimum of Ha line. The classification spectrum is also posted on the IAU Transient Name Sever: https://wis-tns.weizmann.ac.il/object/2018aql