COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2174

                                 Konkoly Observatory
                                 Budapest
                                 1982 July 8

                                 HU ISSN 0374-0676




  PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR BY Dra IN 1979




  Continuous photoelectric monitoring of the flare star BY Dra
has been carried out at the Stephanion Observatory (lambda=-22d49'44",
phi =+37d45'15" ) during the year 1979, 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.,
1982). 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 + 0.099(b-v)_0 + 1.933,
             B-V = 0.698 + 1.008(b-v)_0     ,
             U-B =-1.178 + 1.003(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 19.67 hours of the monitoring time no flare was
observed.

 
                                Table I

                     Monitoring intervals in 1979


Date           Monitoring intervals (U.T,)    Total monitoring time
1979
July
11      20h32m   - 21h01m, 21h03m  - 21h33m, 21h36m - 22h01,     01h  24m
12      19 54    - 20 19 , 20 23   - 20 57 , 21 00  - 21 56,     01   55
13      20 39    - 21 11 , 21 13   - 22 03 .                     01   22
14      19 57    - 20 39 , 20 42   - 21 20 , 21 23  - 21 53,     01   50
19      20 21    - 20 52 , 20 54   - 21 06 , 21 09  - 21 42,
        21 44    - 22 09 .                                       01   41
20      19 38    - 20 14 , 20 17   - 20 52 , 20 55  - 21 24,     01   40
21      19 51    - 20 24 , 20 26   - 20 57 , 20 59  - 21 25,     01   30
22      19 43    - 20 08 , 20 14   - 20 49 , 20 51  - 21 16,     01   25
23      20 31    - 20 54 , 20 57   - 21 27 .                          53
26      19 24    - 19 58 , 20 00   - 20 31 , 20 34  - 20 57,     01   28
27      19 40    - 20 11 , 20 13   - 20 46 , 20 48  - 21 15,     01   31
30      19 22    - 19 59 , 20 01   - 20 32 , 20 34  - 21 07,     01   41
31      19 47    - 20 22 , 20 25   - 21 10 .                     01   20

                    Total   19h40m - 19h67



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