The final decline of Nova (V1974) Cygni 1992 and discovery of an associated extended emission nebulosity

Rosino, L.; Iijima, Takashi; Rafanelli, P.; Radovich, M.; Esenoglu, HASAN; Della Valle, Massimo

The final decline of Nova (V1974) Cygni 1992 and discovery of an associated extended emission nebulosity

Rosino L., Iijima T., Rafanelli P., Radovich M., Esenoglu H. H., Della Valle M.

ASTRONOMY & ASTROPHYSICS, cilt.315, sa.3, ss.463-466, 1996 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 315 Sayı: 3
Basım Tarihi: 1996
Dergi Adı: ASTRONOMY & ASTROPHYSICS
Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
Sayfa Sayıları: ss.463-466
İstanbul Üniversitesi Adresli: Evet

New spectroscopic observations of Nova Cygni 1992 (V1974 Cyg) carried out in 1994-95 have shown a progressive decrease of the ionization level, made evident by the fading or disappearance of the emission lines of [Ne V], [Ne III], [Fe VII], [Fe VI] and [O III], which were outstanding in the 1992-93 spectra. An echelle spectrum obtained at Asiago in October 1995 clearly shows the complexity of the velocity field of the nova.

By scanning three spectra in 1994-95 perpendicular to the direction of the dispersion along Ha, it has been found all around the nova an extended emission nebulosity, having an upper diameter of about 3 arcmin in July 1994 and nearly 4 arcmin in May and October 1995. By assuming that the excitation of this nebulosity was due to the ultraviolet radiation emitted by the nova in the 1992 outburst, we found the distance to the nova about 1.9 +/- 0.1 kpc.