COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                             Number 2998

                                                        Konkoly Observatory
                                                        Budapest
                                                        13 March 1987

                                                        HU ISSN 0374 - 0676


     PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR BY Dra IN 1985

Photoelectric monitoring of the flare star BY Dra has been carried out
at the Stephanion Observatory during the year 1985 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 U colour of the international UBV system.
The telescope and photometer used have been described elsewhere (Mavridis
et. al. 1982). The transformation of our instrumental ubv system to the 
international UBV system is given by the following equations:

    a) For the period June 20- July 10, 1985
       V = v_0 + 0.086 (b-v)_0 + 2.160,
     B-V = 0.376 + 1.035 (b-v)_0,
     U-B =-2.010 + 1.116 (u-b)_0.

    b) For the period August 7 -14, 1985
       V = v_0 + 0.037 (b-v)_0 + 2.020,
     B-V = 0.393 + 1.050 (b-v)_0,
     U-B =-1.710 + 0.963 (u-b)_0.

    c) For the period September 2-8, 1985
       V = v_0 - 0.020 (b-v)_0 + 1.953,
     B-V = 0.451 + 1.007 (b-v)_0,
     U-B =-1.520 + 0.931 (u-b)_0.

  The monitoring intervals in UT as well as the total monitoring time for
each night are given in Table I:


                              Table I
                        Monitoring Intervals

Date           Monitoring intervals (U.T.)           Total Monitoring Time
1985

June
20          20h00m-20h29m,20h33m-21h03m,21h21m-21h54m,
            21 56 -22 21.                                    1h57m
21          19 58 -20 24, 20 26 -20 58, 21 12 -21 44,
            21 46 -22 15, 22 53 -23 20.                      2 26
22-23       19 47 -20 19, 20 27 -20 55, 21 08 -21 43,
            21 45 -22 16, 22 53 -23 25, 23 27 -24 00,
            00 12 -00 35, 00 37 -01 02.                      3 59
23          19 48 -20 17, 20 19 -20 49, 21 02- 21 32,
            21 42 -22 05.                                    1 52
24          20 09 -20 38, 20 40 -21 15, 21 28- 22 00,
            22 02 -22 32.                                    2 06
26          19 51 -20 21, 20 25 -20 55, 21 08- 21 42,
            21 44 -22 14.                                    2 04
27          19 45 -20 17, 20 19 -20 57, 21 11- 21 49,
            21 51 -22 22, 22 41 -23 03.                      2 41
28          19 45 -20 15, 20 17 -20 54, 21 08- 21 40,
            23 13 -23 42.                                    2 08

July
5           20 32 -20 58, 21 01 -21 35, 21 50-22 24,
            22 27 -22 34.                                    1 41
8           19 47 -20 16, 20 19 -20 46, 20 59-21 37,
            21 40 -22 22.                                    2 16
9           20 56 -21 22, 21 25 -21 50.                        51

August
7           20 30 -21 02, 21 04 -21 28                         56
8           20 31 -20 43, 20 45 -21 00, 21 02-21 31            56
9           19 50 -20 22, 20 27 -20 57.                      1 02
10          20 02 -20 20, 20 23 -20 38, 20 41-21 00            52

September
3           20 12 -20 52, 20 56 -21 36                       1 20

                                                  TOTAL     29h 7m

    Any interruption of more than one minute has been noted. During the
29.12 hours of monitoring time no flare was observed.



                   S. AVGOLOUPIS
               Department of Astronomy
              University of Thessaloniki

                  L.N. MAVRIDIS
              Department of Geodetic
                    Astronomy
              University of Thessaloniki

                  P. VARVOGLIS
              Department of Mathematics
                University of Thrace



References:

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