Spectroscopic Classification of M31N 2016-10b and M31N 2016-10d as Classical Novae
ATel #9661; S. C. Williams (Lancaster), M. J. Darnley (LJMU)
on 22 Oct 2016; 11:05 UT
Credential Certification: Steven Williams (scw@astro.ljmu.ac.uk)
Subjects: Optical, Nova, Transient
We report the spectra of two M31 nova candidates taken with the SPRAT spectrograph (Piascik et al. 2014) on the 2-m Liverpool Telescope (Steele et al. 2004). The spectrum of candidate M31N 2016-10d (ATLAS16dlz; ATel #9651) was taken on 2016 Oct 20.14 UT and the spectrum of candidate M31N 2016-10b (PNV J00425245+4118412; ATel #9638) was taken 2016 Oct 21.03 UT.
The 2016 Oct 20.14 spectrum of M31N 2016-10d (ATLAS16dlz) shows strong, relatively broad (Hα FWHM ~ 2400 km/s) Balmer emission. It also shows numerous Fe II emission lines (the 27, 28, 37, 38, 42, 48, 49, 55 and 74 multiplets are all detected). We also observe emission from O I (7774 Å), N I (triplet 3) and Na I (D). This spectrum confirms that M31N 2016-10d is a classical nova eruption in M31 and a member of the Fe II spectroscopic class.
The 2016 Oct 21.03 spectrum of M31N 2016-10b (PNV J00425245+4118412) shows strong, narrow Balmer emission lines, which show evidence of P-Cygni absorption profiles. The nova also shows narrow Fe II emission lines (with the 27, 28, 37, 38, 42, 48, 49, 55 and 74 multiplets all detected, as they are in M31N 2016-10d). M31N 2016-10b shows Na I (D) emission, which is accompanied by a strong P-Cygni absorption component. Emission lines from C I (7115 Å) and Si II (6347 and 6371 Å) are also detected. This spectrum confirms M31N 2016-10b is a classical nova in M31 and we classify it as a member of the Fe II spectroscopic class.
