Spectroscopic confirmation and photometry of the nova candidate M31N 2017-10a
ATel #10887; S. Fabrika, O. Sholukhova, A. Vinokurov, A. F. Valeev, A. Sarkisyan, (SAO RAS), K. Hornoch (Ondrejov), M. Henze (SDSU), A. W. Shafter (SDSU)
on 24 Oct 2017; 08:59 UT
Credential Certification: Sergei Fabrika (email@example.com)
Subjects: Optical, Nova, Transient
We report the optical spectroscopic confirmation of the recent M31 nova candidate M31N 2017-10a (= PNV J00423905+4123006) discovered on 2017-10-14.039 UT by Hornoch et al. (ATel #10849). The spectrum was obtained on 2017-10-19.690 UT using the Russian BTA telescope equipped with the SCORPIO spectrograph, with resolution of 5 A in the 4050 - 5810 A range.
Multicolor photometry of the nova obtained shortly before to the BTA spectrum with the same device gave the following results: B = 19.00 ± 0.08, V = 18.37 ± 0.05, Rc = 17.79 ± 0.06. The measured values indicate significant reddening due to an interstellar extinction produced by a dust in M31 spiral arm obscuring this part of M31 bulge. It is in agreement with rather faint maximum magnitude of the nova (R = 17.5) based on unpublished photometry taken with the 0.65-m telescope at Ondrejov.
The nova shows Balmer emission lines together with numerous, extremely strong Fe II lines. All the single lines have flat-topped profiles. The Fe II lines (4923 and 5018 A) have a FWHM = 2100 ± 60 km/s. The hydrogen H-beta line has a FWHM = 2230 km/s, H-gamma has 1870 km/s with about the same error bars. The widths were corrected for spectral resolution. We conclude that this M31 nova belongs to the Fe II class.