Spectroscopic Classification of SN 2017dgi (=PTSS-17qjg) as a Type Ia Supernova
ATel #10316; Danfeng Xiang, Liming Rui, Xiaofeng Wang, Wenxiong Li (Tsinghua University), Hanjie Tan (Chinese Culture University), Zhijian Xu, Bin Li, Haibin Zhao, Lifan Wang (PMO), Qian Yang, Xuebin Wu (PKU), Junjun Jia, Tianmeng Zhang (NAOC), Zesheng Yang (THU), and Jujia Zhang (YNAO)
on 24 Apr 2017; 10:29 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 390-830 nm) of SN 2017dgi (=PTSS-17qjg),discovered by PMO-Tsinghua Supernova Survey (PTSS, http://www.cneost.org/ptss/ ), on UT Apr.23.56 2017 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 supernovae at 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 2007bd at t = -8 days from the maximum light. After correcting for a redshift of 0.0545 for its host galaxy LCRS B100946.0-053912, an expansion velocity of about 12100 km/s can be derived from the absorption minium of Si II 635.5 line. The classification spectrum is also posted on the IAU Transient Name Sever: http://wis-tns.weizmann.ac.il/object/2017dgi/