COMMISSIONS 27 AND 42 OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Number 3961 Konkoly Observatory Budapest 10 December 1993 HU ISSN 0374 - 0676 Halpha-PROFILE IN THE SPECTRUM OF PLEIONE IN THE BEGINNING OF THE NEW Be PHASE Guo Yulian (1993) reported about significant variations of the Halpha-profile of Pleione (BU Tau) in the beginning of a new Be-phase (December 1991). He draw the conclusion that the H_alpha-profile with double emission peak turned into a single emission peak after December 1991. Observations of the H_alpha-emission line were also carried out by the authors during the same period (September 1991-January 1992) using the Coude-spectrograph with CCD of the 2.6 m-telescope of Crimean Astrophysical Observatory. (A detailed description of this CCD-camera is given in Beriozin et al., 1991.) The linear dispersion of the obtained spectra was 6 A/mm (0.105 A/pixel), the spectral interval 60 A. For one spectrum (1991 December 13) the linear dispersion was 3 A/mm (0.05 A/pixel), the spectral interval 30 A. The S/N-ratio at the continuum was >100. The data reduction was done by using the software of Crimean Astrophysical Observatory. Figure 1 illustrates the obtained Halpha- profiles. All profiles show double emission peaks certainly. In Table 1 the main parameters of the H_alpha-profiles are summarized. ----------------------------------------------------------------------------- No. Date W(A) FWHM(A) I_b I_r I_b/I_r I_abs Delta lambda(A) ----------------------------------------------------------------------------- 1 1991 September 4 28.98 6.92 4.45 4.96 0.90 3.94 2.76 2 1991 December 13 32.86 6.99 5.27 5.38 0.98 4.02 2.81 3 1991 December 14 29.20 6.94 4.70 4.92 0.96 3.91 2.84 4 1992 January 11 30.94 6.81 4.75 5.38 0.88 4.07 2.77 ----------------------------------------------------------------------------- W -equivalent width relative to the adjacent continuum FWHM -full-width-half-maximum intensity of the common Halpha-profile I_b, I_r, I_abs -intensities of the blue, red and central absorption components relatively to the continuum, respectively I_b/I_r -ratio of the intensities of the blue and red peaks Delta lambda -separation of the blue and read peaks Our observational data led to the following conclusions: 1. In the beginning of the new Be-phase the double peak of the H_alpha-emission line remained. The single emission peak obtained by Guo Yulian (1993) is obviously the result of the insufficient spectral resolution of his observations (D=1.15A/pixel). 2. The equivalent width of the H_alpha-emission line does not differ very much from those published by Guo Yulian (W=26A). The intensity of the Halpha-emission line of our observations is higher than that of Guo Yulian (I_max=3.8). 3. Our observations also confirm that the intensity of the Halpha-emission line has increased since the beginning of the new Be-phase. [FIGURE 1] Figure 1. H_alpha-profiles of Pleione. E. V. MENCHENKOVA R. LUTHARDT Astronomical Observatory of the Sonneberg Observatory Odessa State University 96515 Sonneberg Park Shevchenko Germany 270014 Odessa Ukraine References: Beriozin, V. Yu. et al., 1991, Pi`sma Astron. Zhurn., 17, No. 10, 953 [BIBCODE 1991PAZh...17..953B ] Guo Yulian, 1993, Inform. Bull. Var. Stars, No. 3922