Early spectral evolution of Nova Sagittarii 2004 (V5114 Sagittarii)

Aims.We present optical and near-infrared spectral evolution of the
Galactic nova <ASTROBJ>V5114 Sgr</ASTROBJ> (2004) during few months
after the outburst.<BR /> Methods: .We use multi-band photometry and
line intensities derived from spectroscopy to put constrains on the
distance and the physical conditions of the ejecta of V5114 Sgr.<BR />
Results: .The nova showed a fast decline (t<SUB>2</SUB> ≃ 11 days)
and spectral features of Fe II spectroscopic class. It reached
M<SUB>V</SUB> = -8.7 ± 0.2 mag at maximum light, from which we
derive a distance of 7700 ± 700 kpc and a distance from the
galactic plane of about 800 pc. Hydrogen and oxygen mass of the ejecta
are measured from emission lines, leading to ~10<SUP>-6</SUP> and
10<SUP>-7</SUP>~M_ȯ, respectively. We compute the filling factor of
the ejecta to be in the range 0.1-10<SUP>-3</SUP>. We found the value of
the filling factor to decrease with time. The same is also observed in
other novae, then giving support to the idea that nova shells are not
homogeneously filled in, rather being the material clumped in relatively
higher density blobs less affected by the general expanding motion of
the ejecta. <BR />