Spectrum of M31 nova candidate M31N 2016-04a (MASTER OT J004528.12+414117.6)
ATel #9116; S. C. Williams (Lancaster), M. J. Darnley (LJMU)
on 5 Jun 2016; 12:11 UT
Credential Certification: Steven Williams (scw@astro.ljmu.ac.uk)
Subjects: Optical, Nova, Transient
We obtained a spectrum of nova candidate M31N 2016-04a (MASTER OT J004528.12+414117.6; ATel #8950) with the SPRAT spectrograph (Piascik et al. 2014) on the 2m Liverpool Telescope (Steele et al. 2004) on 2016 June 3.19 UT, 54 days after discovery.
The spectrum shows strong, narrow (FWHM < 1000 km/s) Balmer emission. It also shows narrow He I (5016, 5048, 5876, 6678 and 7065 Å) and He II (4686 Å) emission lines. While this combination of lines and line-widths is not common in novae, some eruptions do display such features (e.g. M31N 2007-10a; see Shafter et al. 2011), therefore this spectrum of M31N 2016-04a is consistent with it being a nova in M31. However from this spectrum alone, we cannot rule out the transient being a Galactic dwarf nova.
