... The spectrograph SP-124 at the Nasmyth-1 focus of the 6 m telescope with UAGS camera and Photometrix CCD PM1024 ( m pixel size) was used for the observations. ... Gratings with 300 and 600 grooves/mm were used, resulting in a spectral resolution of approximately 12 and 6 ? ... A He-Ne-Ar lamp was used for wavelength calibration. ... April 6.914 . ... The reduction of the original two-dimensional CCD data included the standard steps such as bias and dark subtraction, flat-fielding, cosmic-ray removal...