Spectroscopic Confirmation of M31N 2015-10a
ATel #8141; S. C. Williams (LJMU), M. J. Darnley (LJMU)
on 8 Oct 2015; 09:08 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)
Subjects: Optical, Nova, Transient
We obtained a spectrum of the luminous nova candidate M31N 2015-10a (PNV J00415937+4117026; see CBAT TOCP and ATel #8134) with the SPRAT spectrograph on the 2m Liverpool Telescope (Steele et al. 2004) on 2015 October 7.9 UT.
The spectrum shows strong Balmer emission, with the FWHM of the Hα estimated at ~ 2,700 km/s. Numerous Fe II lines are also detected in emission (e.g. 4629, 4924, 5018, 5169 and 5317 Å), along with O I features (7477 and 7773 Å).
This spectrum confirms M31N 2015-10a is a luminous classical nova in M31. The emission lines suggest this is a member of the Fe II spectroscopic class, although the Hα emission is broader than that of a standard Fe II nova, implying it may be an Fe IIb nova. Fe IIb or `hybrid' novae sometimes develop He/N type spectra later in the eruption (Williams 1992), therefore continued spectroscopic follow-up of this luminous nova is encouraged.