COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2209

                                   Konkoly Observatory
                                   Budapest
                                   1982 October 18

                                   HU ISSN 0374-0676


      PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR BY Dra IN 1977



   Continuous photoelectric monitoring of the flare star BY Dra has been carried
out at the Stephanion Observatory (l=-22deg49'44",phi=+37deg45'15") during the year 1977,
using the 30-inch Cassegrain reflector of the Department of Geodetic Astronomy,
University of Thessaloniki. Observations have been made with a Johnson dual channel
photoelectric photometer in the B colour of the international UBV system. The
telescope, the photometer and the observational procedure have been described
elsewhere (Mavridis et al., 1981). Here we mention only that the transformation of
our instrumental ubv system to the international UBV system is given by the following
equations:

  U = v0 -0.016(b-v)0 + 1.227,
 
  B-U = 0.684 + 1.057(b-v)o  ,

  U-B =-1.521 + 0.979(u-b)0  .

  The monitoring intervals in UT as well as the total monitoring time for each
night are given in the Table I. Any interruption of more than one minute has been
noted.


                   Table I


             Monitoring intervals in 1977


Date   Monitoring Intervals (U.T.)                    Total Monitoring Time
1977
July
7      20h15m - 20h45m,20h47m - 21h25m, 21h27m - 22h27m.   02h 08m
8      19 29  - 20 04, 20 07  - 20 36 , 20 38  - 21 07,
       21 57  - 22 23.                                     01  59
10     20 40  - 21 18, 21 20  - 21 53,  21 55  - 22 22.    01  38



                      Total 1977      05h 45m =05.75h




   During the 5.75 hours of the monitoring time no flare was observed.


Acknowledgements: The support of the National Hellenic Research Foundation for
this research is gratefully acknowledged.





            L.N. MAVRIDIS and P. VARVOGLIS
            Department of Geodetic Astronomy
             University of Thessaloniki





Reference:
Mavridis, L.N., Asteriadis, G., and Mahmoud, F.M.: 1982, in E. Mariolopoulos,
           P.S. Theocaris, and L.N. Mavridis (Editors) Compendium in
           Astronomy, D. Reidel, Dordrecht-Holland, p. 253. [BIBCODE 1982coas.conf..253M ]