Spectroscopic Classification of SN 2017egm as a Luminous Type II Supernova
ATel #10442; Danfeng Xiang, Hao Song, Xiaofeng Wang, Liming Rui (Tsinghua University), Feng Xiao, Tianmeng Zhang (NAOC), and Jujia Zhang (YNAO)
on 30 May 2017; 14:16 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 370-850 nm) of SN 2017egm(=Gaia17biu), discovered by the Gaia Satellite, on UT May 26.6 2017 with the 2.16-m telescope (+BFOSC) at Xinglong Station of National Astronomical Observatories of China (NAOC). The spectrum shows a blue continuum and is overall consistent with that of a type II supernova in its early phase. 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 about 4 days after explosion. Giving a recession velocity of 9210 km/s for its host galaxy NGC 3191, SN 2017egm appears bright (i.e., ~-19.0 mag, according to the discovery magnitude) for normal SNe IIP or SNe IIL. Giving its relatively high luminosity, further observations are encouraged. Our classification spectrum is also posted on the IAU Transient Name Sever: http://wis-tns.weizmann.ac.il/object/2017egm/
