COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                       Number 3074



                                          Konkoly Observatory
                                          Budapest
                                          25 August 1987

                                          HU ISSN 0374-0676


     HYDROGEN EMISSIONS ON LOW-DISPERSION SPECTROGRAMS OF B-STARS

  The presence of hydrogen emission lines (often accompanied by emission
lines of singly ionized metals) in the visible wavelength range of the B-type
spectra is a rather frequent phenomenon. Nevertheless, its place in the context
of stellar evolution theories is not yet definitely elucidated.
    It is well known that in some cases a Be- or a B-shell star loses its
emission and becomes a normal B-star, or vice versa. This is the reason why
the detection of emission lines in B-spectra and the study of their variations
with time is of particular interest.
  The objective-prism surveys may appear rather useful in this kind of work.
A sufficiently strong emission in the hydrogen lines can easily be detected at
a nominal dispersion.
  The observations presented here are obtained in the course of inspection
of objective-prism Kodak-plates taken in 1974-75 on the 70-cm meniscus telescope
of the Abastumani Astrophysical Observatory (USSR), supplied with an 8-deg
objective prism. The reciprocal dispersion of the spectra is 166 A/mm at H-gamma,
their extent being from H-beta up to 3500 R. We disposed of red plates too, so that
we could observe the region of the H-alpha -line as well. The spectra are widened
to 0.4 mm. No attempt has been made for assigning spectral classes to the stars
in question. The emission features are observed on two or three plates taken
in close periods of time.
  The stars are listed below. When no identification numbers are available,
we provide identification charts. As far as we know, five of the stars in our
list have not yet been observed as emission line stars; three others are 
presented in the Catalogue of Be-stars (Jaschek and Egret, 1982).

LIST of the observed stars:

BD+61 0154. Sharp emissions in H-alpha, H-beta.
BD+59 0115. H-beta emission; Be:
BD+61 0074. H-beta emission; Be:
       (the red spectra of BD+59 0115 and BD+61 0074 are overexposed, so
       that H-alpha is not observable)
BD+59 2829. H-beta emission. (Jaschek and Egret, 1982).
BD+61 0122. H-beta emission. (Jaschek and Egret, 1982).
BD+62 0001. H-beta emission. (Jaschek and Egret, 1982).
No. 1 ident.chart ( star A is BD+27 3400, star B is BD+26 3561).
          Sharp emissions in H-alpha, H-beta, H-gamma, H-delta.
No. 2 ident. chart (star A is BD+60 0117, star B is BD+59 0125).
          Emissions in H-alpha, H-beta, H-gamma.


                         [FIGURE 1]

               Figure 1. Identification charts




                          TSVETANKA RADOSLAVOVA
                     Department of Astronomy with National
                     Astronomical Observatory Bulgarian
                     Academy of Sciences, 72 Lenin Blvd.,
                     1784 Sofia
                     Bulgaria


Reference:
Jaschek, M., Egret, D., 1982 In:"Be Stars", Proc. IAU Symp. No.98, p.261 [BIBCODE 1982IAUS...98..261J ]