Spectroscopic classification of M31N 2017-04b as a classical nova
ATel #10451; S. C. Williams (Lancaster), M. J. Darnley (LJMU), K. Hornoch (Ondrejov)
on 1 Jun 2017; 19:53 UT
Credential Certification: Steven Williams (firstname.lastname@example.org)
Subjects: Optical, Nova, Transient
We obtained a spectrum of classical nova candidate M31N 2017-04b (PNV J00424610+4118390; ATel #10317) with the SPRAT spectrograph (resolution R ~ 350; Piascik et al. 2014) on the 2-m Liverpool Telescope (Steele et al. 2004) on 2017 May 27.20 UT.
The spectrum shows strong Balmer emission lines (Hα, Hβ, Hγ) and we measure the FWHM of Hα to be ~1300 km/s. The spectrum also displays N II 5001 Å and N III 4638 Å emission lines. Additionally, we detect emission from N II 5679 Å, [N II] 5755 Å and He I 5876 Å. This spectrum confirms that M31N 2017-04b is a classical nova in M31 and is consistent with it being significantly beyond peak brightness.