The Be star 14 Lac (HD 216200) holds our attention since it shows on unusual time scales a variability pattern which is fairly common among these objects.
Slettebak (1982) classifies it as a B4 III star;
Uesugi & Fukuda (1982) assign
to its spectral lines a Doppler broadening
= 220 km s -1 ;
Goraya & Gurm (1987) get, through their continuum spectrophotometry, an
estimate of its temperature and gravity:
.
In 1950-51 Walker (1952), using this object as a comparison star in his
differential photometry of 16 Lac, observed a light variability
on a time scale
of days. Andrews (1968) suspected it of being a Be star from
a comparison of
photometric indices. The first spectroscopic evidence of this
fact is due to
Wackerling (1970), which observed a weak emission in H
.
The evaluations of the possible period or pseudoperiod of the light variations
range from the 
20 days of Hill et al. (1976) to the 5 days of Mantegazza (1980). Due to these time scales,
and to the apparent non-sinusoidal shape of the light curve, the
variability shown by 14 Lac has been generally ascribed to a tidal strain
produced by the presence of a companion star. In an annual report from the
Dominion Astrophysical Observatory (Richardson 1977) we find a
trace of a spectroscopic study performed by G. Hill, which seemed to
show evidence of a double-lined binary system with a period of 10
days. Unfortunately, this work has never been published. A quotation of
Hill's spectroscopy in Pavlovski et al. (1994) makes up for
that gap: combining the above quoted observations with their archive
photometry, these authors seem now to raise 14 Lac from the rank of
ellipsoidal variable to the one of eclipsing binary, giving for its period
the value of 
. More details are going to appear in a publication
announced in that note.
Since the position of 14 Lac in the sky is close to the one of o And, we took advantage of an observational campaign on this well-known Be star organized in 1992 including also 14 Lac in our program. The photometric and spectroscopic data obtained on that occasion, combined with a re-analysis of the previous available photometry, allowed us to reach some conclusions presented in this paper.