Spectroscopic Classification of SN 2017eaw in NGC 6946 as a Young Type IIP Supernova

ATel #10376; Danfeng Xiang, Liming Rui, Xiaofeng Wang (Tsinghua University), Jianning Fu (Beijing Normal University), Feng Xiao, Tianmeng Zhang (NAOC), and Jujia Zhang (YNAO)
on 15 May 2017; 01:53 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Xiaofeng Wang (wang_xf@mail.tsinghua.edu.cn)

Subjects: Optical, Supernovae, Transient

Referred to by ATel #: 10377, 10378, 10380, 10381, 10394, 10401, 10407

We obtained an optical spectrum (range 370-860 nm) of SN 2017eaw, discovered by Patrick Wiggins, on UT May 14.79 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 young type IIP supernova at 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 1999gi at t = -7 days from the maximum light. After correcting for a redshift of 0.000133 for its host galaxy NGC 6946, an expansion velocity of about 10600 km/s can be derived from the absorption minium of Ha line. This is the tenth SN recorded in this nearby spiral galaxy over the past 100 years. NGC 6946 is also the most prolific galaxy for SNe. Follow-up multiband observations are encouraged. Our classification spectrum is also posted on the IAU Transient Name Sever: http://wis-tns.weizmann.ac.il/object/2017eaw/