Spectroscopic confirmation of M31N 2015-11a and photometry of the nova candidate M31N 2015-11b
ATel #8287; S. Fabrika, O. Sholukhova, A. F. Valeev (Special Astrophysical Observatory), K. Hornoch (Astronomical Institute, Ondrejov), M. Henze (CSIC-IEEC), A. W. Shafter (SDSU)
on 16 Nov 2015; 10:58 UT
Credential Certification: Sergei Fabrika (fabrika@sao.ru)
Subjects: Optical, Nova, Transient, Variables
We report optical spectroscopic confirmation of the recent M31 nova candidate M31N 2015-11a (= PNV J00442840+4132329) discovered 2015/11/06.990 by Gloria Sala et al. (ATEL #8267). The spectral data were obtained on 2015 Nov. 14.901 UT using the Russian BTA telescope equipped with the SCORPIO spectrograph. The spectra were taken with a spectral resolution of 5.1 Å in the spectral range of 4060 - 5850 Å. The nova shows very strong Balmer emission lines (H-delta, H-gamma, H-beta) in the spectral range and at least 12 Fe II emission lines. The strongest Fe II lines are 4922, 5018 and 5169 Å. H-beta line does not show a P Cyg type profile, but the H-gamma and H-delta lines do. The difference between the H-gamma and H-delta center of gravity and blue edges of their absorption P Cyg profiles is about 2500 km/s. The radial velocity of the H-beta line (center of gravity, heliocentric) is +170 km/s, however at the nova location in M31 the radial velocity is -75 ± 25 km/s (21-cm measurements, Corbelli et al., 2010, Astron. Astrophys. 511, A89). The width of the H-beta line corrected for the spectral resolution is FWHM = 1100 km/s, two Fe II lines (5018 and 5169 Å) have FWHM ~ 1200 km/s. The nova belongs to the Fe II type.
Photometry of the nova obtained shortly prior to the spectroscopy with the same device gave V = 19.57 ± 0.09.
We have obtained photometry of the nova candidate M31N 2015-11b (= PNV J00423708+4110137) discovered 2015/11/11.861 by Kamil Hornoch et al. (ATEL #8278). The photometry was obtained with the same device on 2015 Nov. 14.931UT gave V = 19.58 ± 0.010.
