Based on observations collected at the European Southern Observatory (ESO), La Silla, Chile.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

Note that an alternative view is expounded by Lockley et al. (1997) who explain the radio emission (and X-ray emission) of V Sge as originating in a colliding wind binary, in agreement with an optical study by these authors and by Gies et al. (1998).

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... hydrogen

Thus, the emission line at the position of H $\beta$ , which is used to define the V Sge stars, is, in fact, a He II line.

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.

... line

Incidentally, the O VI 3811/34 line was observed by CSH right at the peak of the long-term light curve in December 1991 (Fig.17), deviating strongly from their model, while normally its strength is about twice as low, in better agreement with their model (see their Fig.6).

.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.