Astron. Astrophys. 342, 756-762 (1999)

2. Spectroscopic observations

CCD spectrum of  Peg has been obtained with an echelle spectrometer GECS on 1-m telescope (Special Astrophysical Observatory of the Russian Academy of Sciences, Russia, Northern Caucasus). The detailed description of the spectrometer is given by Musaev (1993). The resolving power was 24000, S/N 250. The spectrum consists of 97 spectral orders having total useable length 5000 Å (from 3500 Å to 8500 Å). Observed spectrum has been reduced using DECH20 code (Galazutdinov, 1992). This code includes: (1) spectra extraction from the images, (2) dark and cosmic hits subtraction, (3) flat-field correction, (4) wavelength calibration, (5) equivalent widths measurement, etc.

The internal accuracy of the equivalent widths is of the order of 5%. This estimate is based on the comparison of values derived from the lines present in two overlapping spectral orders. Measured equivalent widths of selected N ii lines are presented in Table 1.

Table 1. Equivalent widths of selected nitrogen lines

© European Southern Observatory (ESO) 1999

Online publication: February 23, 1999
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