COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1749

                                Konkoly Observatory
                                Budapest
                                1980 February 27


          FLARE STARS IN THE PLEIADES REGION


In the summer 1979 we started a patrol observation programme of flare stars in
stellar aggregates at the National Astronomical Observatory of Bulgaria (on
Mt. Rodopy, at Rojen, 1760 m above sea level). The observations were made with
the 50/70/172 cm Schmidt telescope which had been previously mounted in
Potsdam, now being one of the telescopes at the observatory in Rojen.

From October to December 1979, 27 patrol plates were taken by the method of
equal multiple exposures. The observations were made on ORWO ZU-21 emulsion
using Schott UG-2 filter. The limiting magnitude in U-band was about 17.3m
and the field covered 14.4 square degrees centered on Alcyone. The scale on
the telescope is 122" per millimetre. The total effective time of observations
is 26h50m, they include 161 single 10 minute exposures.

The data of observed flare stars are summarized in Table I.

Table I

Rojen   HII    RA          D      m_u   Delta m_u    Date     Ident. Byurakan
Nos                               min.                            Nos.

1       133   3h 30.5m   24d 23'  16.9m   1.4m     09.12.1979    397
2       335      38.4    23  45   16.0    0.9      17.10.1979     73
3                45.0    22  22   18.4    3.8      17.10.1979    475
4                45.0    23  38  :20.5   >6.1      17.10.1979
5      3101      45.7    22  53   15.8    2.6      18.10.1979    111

The successive columns give the following data:

1 Rojen designation,
2 the Hertzsprung numbers,
3-4 coordinates for 1900.0,
5 photographic magnitude of the stars at minimum,
6 amplitude of the observed flare,
7 date of the flare events (U.T.),
8 identification of the flare stars by the Byurakan lists.


M.K. TSVETKOV
S.A. TSVETKOV
ASSYA G. TSVETKOVA
Department of Astronomy with National Astronomical Observatory
Bulgarian Academy of Sciences
Sofia-1000, 7th November Str.1
Bulgaria