Our spectra do not cover the region around H
, but some
information on the strength and variability of the H
line can be
derived from published 
and Geneva 7-color photometry. We,
therefore, have added to Table 1 (click here) the observed 
index, and we calculated the corresponding index
.
According to Cramer (1984, 1994), the excess
is the signature of the presence of an
emission feature in the H
line (a strong and variable excess
points to the presence of a strong, respectively variable, emission component).
We refer to Fig. 5 (click here) for an overview of all our observed
H
line profiles.
Emission at H
and H
during 1957-1963 was reported by
Buscombe (1970). Infrared excess was detected by
IRAS (Oudmaijer et al.
1992). Despite its rather large 
, our spectrum
shows moderate H
and OI emissions. He I
6678 is in absorption and Paschen lines seem to be completely
filled in by emission.
HD91188 = SX Vel is a short-period (
) photometric
variable that was extensively observed by
Balona et al. (1992), for a phase diagram see Fig. 6 (click here).
Years ago Albers (1969) reported
emission at H
and probable emission at OI 
7775. We
have found a weak H
emission while OI 
7775 is in
absorption. The equivalent width of this line is rather large when
compared to the average observed in non-shell Be stars of the same
spectral type (Jashek et al. 1993). This could be evidence of a
possible transition into a shell phase. He I 
6678 and Paschen
lines are observed in absorption. In addition, weak
(
0.5Å) FeI emission at 
7955 and 7959 seems to
be present.
The radial velocities of the P11-P15
Paschen lines show a mean of 19 
11 km s
, slightly larger than
the radial velocity derived from the H
profile (-16 km s
).
As absorption lines are formed close to the stellar photosphere and emission
lines arise from the circumstellar gas, this fact
probably indicates radial gas motions in the envelope.
This B6IIIe star shows weak emission at H
and Paschen lines in
absorption. This is a very ill-studied star: the SIMBAD database does
not give a single reference to previous studies.
Table 1: The observed stars. The exposure time and the mean signal to
noise ratio at the continuum level are given for each spectrum.
Magnitudes and spectral types are from Hoffleit et al. (1983).
is the calculated 
index derived from
the data published by Rufener (1988), 
is the observed
Strömgren 
index taken from the catalogue of Hauck & Mermillod
(1990), except for HD128293 for which the value by Reed (1996) was used
Table 2: (available electronically) The normalized spectra
(SAMPLE; FULL TABLE WILL BE ELECTRONIC)
Table 3: Equivalent widths (Å) of spectral lines seen in our
spectra. A slash separates equivalent widths measured with different
criteria (see text). The H
line in HD 94910 (AG Car) is
blended with [NII] emission
Table 4: Radial velocities (km s
) of spectral lines seen
in our spectra
This is a well-studied Luminous Blue Variable (LBV) surrounded by a
prominent ring nebula--see Humphreys & Davidson (1994) for a review
of LBVs including AG Car, and van Genderen et al. (1996) for a discussion
of the photometry. We have observed AG Car early in the phase of a
new increase in brightness after a low-brightness phase lasting
3 years. The star was at about 
during our
observation (see Fig. 7 (click here) where its estimated position
corresponds with the head of the vertical arrow). Our spectrum shows a
very strong H
emission peak (see Fig. 5 (click here)) flanked
by weaker emissions probably
corresponding to [NII] 6548 and 6584, which in our spectral resolution
should, in fact, not be resolved. Helium emissions are also present.
The data plotted in Fig. 7 (click here) are from different sources, viz. Kilkenny et al. (1985), van Genderen et al. (1988, 1990), Leitherer et al. (1994) and data from the Long-Term Photometry of Variables project (LTPV, Sterken 1983, 1993) and published by Manfroid et al. (1991, 1994) and Sterken et al. (1993, 1995).
Shallow, slightly symmetric double H
-H
emissions were
reported by Andersen & Nordstrom (1977). A strong double emission was
observed at H
on August 9, 1978 by Jaschek & Jaschek (1992).
Our spectra show H
and OI 
8446 in emission. Paschen
lines and He I 
6678 are in absorption.
The radial velocities of the P11-P15 Paschen absorption
lines show a smooth negative progression with an average value of
66 
22 km s
whereas the H
and OI 
8446
emission lines and the He 
6678 line show velocities
remarkably different with a mean of 5 
3 km s
.
Emission in H
and H
with a mean equivalent width of 3.2
Å was observed by Buscombe (1970). His radial velocity data
(Buscombe 1962) show strong variations of both the emission and
absorption component on time scales of 2-3 months. H
double
central emission with a broad absorption line on August 8, 1978 was
reported by Jaschek
& Jaschek (1992). Our spectra also show the presence of weak
H
emission.
This star was observed by one of us in the survey reported by
Sterken & Jerzykiewicz (1983), and was classified 
, i.e.
significant light variations (in the Strömgren b band) were
detected in HD128293, the second comparison star HD131058, or in both.
The associated u,v and y data have never been analysed, and could
perhaps answer the question which of both stars is the dominant
variable. Unfortunately, the data could not be retrieved by us from
their repository.
Several years ago this late-type B star showed a weak diffuse
roughly symmetric H
emission (Andersen &
Nordstrom 1977). Our spectrum also shows a low-emission star
characterized by a weak H
emission upon broad absorption wings.
Paschen lines are observed in absorption.
The discrepant values of the
radial velocities found in P13 and P11
could indicate contamination by CaII and/or NI at P13 and FeI 
8864 at P11. When comparing the mean radial velocity of Paschen lines
(54 
17 km s
) with the H
radial velocity (-16 km s
)
it seems that the envelope is radially moving out.
Observations in the 21 cm hydrogen line have
revealed that this star is immersed in a high-velocity interstellar cloud
probably arising from an old supernova remnant (Little et al. 1994).
The optical spectrum has shown central double emissions at H
,
H
and H
upon underlying absorption lines on August 9,
1978 (Jaschek & Jaschek 1992). H
emission with 
Å was observed on October 22, 1981 by Andrillat (1983).
Our spectrum shows a stronger
H
emission and weak He 
absorptions. OI
are in emission. Paschen lines seem to be
completely filled by emission.
Acknowledgements
This research was supported by the Dirección de Investigación de la Universidad de Concepción, Chile, PI # 95.11.11.1-1. This research has made use of data obtained through the High Energy Astrophysics Research Center Online Service, provided by the NASA-Goddard Space Flight center. CS acknowledges a research grant from the Belgian Fund for Scientific Research (NFWO). Part of the data discussed in this paper were collected under observing program ESO 57D-0133. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France.