Optical Spectroscopy of two Novae M31N 2007-11b and M31N 2007â11c
ATel #1314; E. Barsukova (Special Astrophysical Observatory, SAO), A. Valeev (SAO),O. Sholukhova (SAO), S. Fabrika (SAO), V. Burwitz (Max-Planck-Institute fuer extraterrestrische Physik, MPE), W. Pietsch (MPE)
on 30 Nov 2007; 10:49 UT
Credential Certification: Barsukova E.A. (bars@sao.ru)
Subjects: Optical, Binary, Cataclysmic Variable, Nova, Star, Variables
We have obtained spectra of M31N 2007-11b and M31N 2007-11c novae
witn the Russian 6m telescope in a range 370 - 755.5 nm with
spectral resolution 1.2 nm. M31N 2007-11c spectrum has been
taken on 2007 Nov 17.65 with 1800 sec exposure time, M31N 2007-11b
has been taken on 2007 Nov 17.69 with 2400 sec exposure.
M31N 2007-11c (ATEL#1275):
Our spectrum was obtained about 4.4 day after the discovery and
0.70 day after previous spectroscopy (ATEL#1292).
We confirm the spectrum description of M31N 2007-11c given in ATEL#1292.
In addition in our spectrum the FeII emission lines are observed up to
750 nm, FeII lines dominate in all the spectrum.
We have found many fainter emission lines of NII, the NII 567.9 nm line
shows P-Cyg line profile. NaID lines are in emission with P-Cyg profile,
the deepest part of the P-Cyg is shifted approximately on -2400 km/s.
The same shift is observed in hydrogen P-Cyg lines. Hydrogen line widths
corrected for instrumental profile are FWHM(H_alpha) = 2395 km/s and FWHM(H_beta) =
2870 km/s, EW(H_alpha) = -33 nm. The H_alpha line width is notably
bigger in our spectrum than in previous spectroscopy.
Emission lines of CaII H and K are also present.
We confirm the object is a FeII class nova, in the P_fe phase (Williams,
AJ,104,725,1992).
M31N 2007-11b (ATEL#1257):
Our spectrum was obtained about 15.4 day after the discovery and 4.40 day
after the first spectroscopy (ATEL#1276).
The spectrum has flat continuum, very strong Balmer emission lines
and strong emission lines of HeI and HeII 468.6 nm.
Fainter emission lines of NIII and FeII were also detected, the
strongest of them are the NIII 464.0 nm, FeII 516.9, 531.7 nm lines.
Hydrogen line widths are FWHM(H_alpha) = 1110 km/s, FWZI(H_alpha) = 4070
km/s, and FWHM(H_beta) = 1140 km/s, EW(H_alpha) = -85 nm. The line
widths (FWHM) became 300 km/s less than in previous spectrum (ATEL#1276).
We confirm the He/N class of the nova.
Link to figures of novae' spectra
