2. Spectroscopic observations
All the programme stars, except P75, were observed at the 2.5m Isaac Newton telescope (INT) with the Intermediate Dispersion Spectrograph (IDS) during a four night run in August 1995. We used the 235mm camera, AgRed collimator, gratings R1200Y and H1800V and a TEK 1124x1124 CCD detector. For each star we give in Table 1 the Prosser (1993) number and V-magnitude, date of the observation, dispersion (resolution 2 pixels), and exposure time. One of the stars was observed with the 3.5m telescope at Calar Alto observatory, using the TWIN spectrograph, T06 grating in the red arm and a TEK chip.
Table 1. Observing log
Each spectrum was reduced by a standard procedure using IRAF 1, which included debias, flat field, optimal extraction and wavelength calibration using CuNe arc lamps. Fig. 1 displays the full range of the final spectra.
© European Southern Observatory (ESO) 1997
Online publication: July 3, 1998