Based on observations made with the 1.52 m ESO telescope at La Silla, Chile.

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Appendices A and B are only available in electronic form at http://www.aanda.org

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... HD 45166

The telluric lines in absorption have a much higher TVS in our data (28%), and, therefore, those lines can be easily identified and differentiated from the stellar lines. On the other hand, the interstellar lines should not appear in the spectrum of the TVS. The TVS can be a useful method to distinguish between the several types of lines present in a rich emission and absorption line spectrum such as in HD 45166.

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