COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 875

                                Konkoly Observatory
                                Budapest
                                1974 March 14

     UBV PHOTOELECTRIC PHOTOMETRY FOR FLARE STARS
            IN THE PLEIADES CLUSTER


   Seventeen stars in the Pleiades cluster were observed in
the UBV system of Johnson and Morgan (1953). The observations
were made with the 1 m telescope of the Lunar and Planetary
Laboratory on Mount Lemmon. The stars observed were taken from
two lists of flare stars given to the author in advance of 
publication by Dr. G. Haro. He has recognized these stars as members 
of the Pleiades cluster, with the exception of HII 2591
and HII 3065. Most of the stars in this work have been observed
previously by Johnson and Mitchell (1958). Initially at least
two observations for each star were planned in order that the
new list have the same weight as the one published earlier
(Iriarte 1967). This was not accomplished in every case.
   The observations are listed in Table 1. Column 1 gives
the original flare star numbers as given in Haro's list. The
meaning of the letters preceding the numbers is as follows:
T (Tonantzintla), A (Asiago), B (Byurakan), K (Konkoly). Column
2 gives the Hertzsprung (1947) number of the star; Columns 3,
4., and 5, the V magnitudes and the B-V and U-B colors, 
respectively; Column 6, the number of observations; Column 7, the
spectral types. The classification of the spectral type of
HII 1100 is by Wilson (1963), the remaining by Kraft and 
Greenstein (1969).
   Great care was exercised in the standardization of the region. 
A considerable amount of observing time was expended on
standard stars. HII 1084, a reddened A0V star member of the
Pleiades cluster was used as a secondary standard. An analysis
of the data will be published at an early date.


                        BRAULIO IRIARTE ERRO
                        Instituto Nacional de
                        Astrofisica
                        Optica y Electronica
                        Tonantzintla, Mexico.


                    Table 1

Original                                             Spectral
flare star   Star           V     B-V    U-B     n   type 
number                                               

T56b         HII 97       12.65   1.08   0.87    3
A90          HII 324*     13.12   1.02   0.79    4
T160         HII 347      14.04   1.41   -       2   K7Ve
T45          HII 590      14.34   1.37   -       2
T13          HII 686      13.38   1.27   -       1
B212         HII 1029     14.21   1.52   -       1
A148         HII 1039     13.07   1.23   0.79    2
T43b         HII 1100     12.13   1.17   0.86    2   dK3e
T58b         HII 1553     12.35   1.13   0.76    1
T48b         HII 1883*    12.64   1.07   0.75    3
T9b          HII 2034*    12.51   1.04   -       2
T88          HII 2193     14.18   1.47   -       1   K6Ve
K23          HII 2368     14.02   1.34   -       1
B294         HII 2591     13.28   1.23   0.92    1
T109         HII 2927     13.80   1.34   -       1   K4Ve
B295         HII 3065     12.97   1.39   -       2
T59b         HII 3197     12.04   1.15   0.73    2

Notes to Table 1
324 observed twice in U
1883 observed twice in U
2034 U was observed on two different nights. The values
             are consistent but they appear bright: U-B = 0.38
             and U-B = 0.33.





References:
                                  
Johnson, H.L., and Mitchell, R.I., 1958, Ap.J., 126, 134. [BIBCODE 1957ApJ...126..134J ]
Johnson, H.L., and Morgan, W.W., 1953, Ap.J., 117, 313. [BIBCODE 1953ApJ...117..313J ]
Iriarte, B., 1967, Bol. Tonantzintla y Tacubaya, 4, 28. [BIBCODE 1967BOTT....4...79I ]
Kraft, R.P., and Greenstein, J.L., 1969, Low Luminosity stars,
     ed. S.S. Kumar (Gordon and Breach Science Publishers).
Wilson, O.C., 1963, Ap.J., 138. 832. [BIBCODE 1963ApJ...138..832W ]