COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 2210

                                  Konkoly Observatory
                                  Budapest
                                  1982 October 18

                                  HU ISSN 0374-0676





     PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR BY Dra IN 1980





  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 1980,
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:

V = v0 +0.011(b-v)0 + 3.191   ,

B-V = 0.569+ 1.022(b-v)0      ,

U-B =-1.858 + 0.962(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.

   During the 30.93 hours of the monitoring time no flare was observed.




                            Table I


                Monitoring Intervals in 1980

Date            Monitoring intervals (U.T.) Total  Monitoring Time
1980
July
4        21h04m - 21h34m,21h37m  - 22h03m.             00h 56m
5        20 35  - 21 24.                               00   49
6        20 27  - 20 49, 20 58   - 21 36,21 40 -22 13. 01   33
7        20 42  - 21 09, 21 13   - 21 45.              00   59
9        19 52  - 20 23, 20 26   - 21 06,21 07 -21 56. 02   00
10       20 40  - 21 09, 21 11   - 21 42,21 45 -22 32. 01   47
24       21 35  - 22 05, 22 08   - 22 35,22 38 -23 12. 01   31
26       20 24  - 20 52, 20 55   - 21 33,21 35 -21 38,
         21 39  - 22 19.                               01   49
27-28    20 07  - 20 46, 20 49   - 21 22,21 25 -21 56,
         22 11  - 22 42, 22 45   - 23 18,23 24 -23 56,
         00 06  - 00 32, 00 47   - 01 20.              04   18
28       20 21  - 21 16, 21 19   - 21 58,22 00 -22 36. 02   10
29       20 06  - 20 29, 20 37   - 20 59,21 02 -21 34. 01   17
August
16       19 18  - 19 45, 19 48   - 20 16,20 22 -20 31,
         20 37  - 20 47.                               01   14
19       19 53  - 20 08.                               00   15
21       20 05  - 20 38, 20 42   - 21 13.              01   04
22       19 23  - 19 57, 20 00   - 20 34,20 51 -21 31,
         21 34  - 22 07.                               02   21
24-25    21 00  - 21 34, 21 38   - 22 13,22 40 -23 17,
         23 20  - 23 53, 00 21   - 00 57,01 01 -01 24. 03   18
26       19 40  - 20 13, 20 17   - 20 51,21 05 -21 38,
         21 41  - 22 24.                               02   23
27       19 27  - 19 51, 19 57   - 20 28,20 44 -21 14,
         21 18  - 21 49, 22 05   - 22 33,22 35 -23 07. 03   08
31       20 47  - 21 14.                               00   27



               Total 1980            30h 56m = 30.93h 




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





  G. ASTERIADIS(1), S. AVGOLOUPIS(2), L.N. MAVRIDIS(1), P. VARVOGLIS(3)





     (1) Department of Geodetic Astronomy, University of Thessaloniki
     (2) Department of Astronomy, University of Thessaloniki
     (3) Department of Mathematics, University of Thrace





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 ]