Astron. Astrophys. 329, 131-136 (1998)

4. Spectral observations

4.1. Optical spectroscopy

In Fig.  3 the optical high-resolution spectra of the three stars in the spectral regions around 5885 Å, 6563 Å, and 8685 Å are shown. The following features should be noted.

Fig. 3a-c. Normalised spectra of the three program stars around 5885 Å, 6563 Å, and 8685 Å. The star HD 142666 shows CS absorption lines, while the stars HD 139614 and HD 144432 show CS emission lines.

In HD 139614, H displays a single-peaked emission profile; the 5876 Å HeI line is seen as a broad CS emission profile; the NaI and lines are in absorption, with a width which is similar to that of the NI lines at 8680 and 8688 Å; the Paschen 13 line of HI ( 8665 Å) appears in absorption.

HD 142666 shows a H double-peaked emission profile with a deep absorption reversal reaching well below the adjacent continuum; a broad HeI 5876 Å absorption is observed; the NaI D profile consists of a narrow, strong component, superimposed on a broader (  = 56 km  ) component; P13 is seen in absorption.

HD 144432 also shows a double-peaked H profile, with a deep absorption reversal going below the continuum, but here the red component is much stronger than the blue component; a broad HeI 5876 Å emission line is observed; the sodium lines appear in emission, with two narrow IS absorption components; P13 is now seen in emission.

A value for was derived from other spectra showing photospheric lines and a values of 13 km  for HD 139614, 56 km  for HD 142666 and 54 km  for HD 144432 were found.

4.2. Near-IR spectroscopy

In Fig. 4 the obtained near-IR spectra around the HeI 1.08 m line are shown. The observed features are summarised in Table  4.

Table 4. Summary of the near-IR spectral features for the program stars.

Fig. 4a-c. The three program stars around the HeI 1.08 m; flux is in arbitrary units. The star HD 142666 shows HeI in absorption, while the star HD 139614 shows CS emission lines, and HD 144432 shows an inverse P Cygni feature.

© European Southern Observatory (ESO) 1998

Online publication: November 24, 1997
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