COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      Number 1907

                                  Konkoly Observatory
                                  Budapest
                                  1981 January 7

                                  HU ISSN 0374-0676


PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR BD+16d2708 IN 1976


	Continuous photoelectric monitoring of the flare star
BD +16d2708 has been carried out at the Stephanion Observatory
(lambda=-22d49'44",phi=+37d45'15") during the year 1976, 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 and photometer will
be described elsewhere. Here we mention only that the  transformation 
of our instrumental ubv system to the international UBV
system is given by the following equations:
		   V = v_0 - 0.008(b-v)_0+2.292,
		(B=V)= 0.737+ 1.043(b-v)_0,
		(U-B)= -1.798+ 1.131(u-b)_0.
	The monitoring intervals in UT as well as the total monitoring 
time for each night are given in the Table I.       
			Table I
		Monitoring intervals in 1976
Date   Monitoring intervals (UT)     Total Monitoring    sigma(U.T.)
1976 					  time
May
7-8   20h09m-29h48m,21h50m-22h16m, 		  0.10(21h25m),0.10
      22 18 -22 48, 23 00 -23 12, 		  (21 54),0.11(22 20),
      23 45 -00 08, 00 10 -00 43,  	          0.09(23 06),0.07
      00 45 -01 20, 01 22 -01 51. 	03h36m    (23 46),0.06(00 13),
					      	  0.06(00 47),0.07
						  (01 24).
21-22 19 55-20 20, 20 22-20 53, 		  0.06(19 58),0.06
      20 55-21 29, 21 38-22 08, 		  (20 24),0:05(20 57),
      22 11-22 43, 22 45-23 23,		 	  0.05(2141),0.05
      23 31-00 16, 00 18-00 59, 		  (2213),0.06(2248),
      01 01-01 48. 			05 23 	  0.06(23 34),0.07
						  (00 28),0.09(01 33).

26-27 20 56-21 27, 21 29-21 58, 		  0.06(21 01),0.06
      22 00-22 31, 22 42-23 13, 		  (21 33),0.06(22 03),
      23 16-23 47, 23 49-00 29, 		  0.06(22 45),0.07


                                     Table I (cont.)
Date      Monitoring intervals (UT)     Total Monitoring  sigma(U.T.)
                                           time
1976
May      
26-27     00h40m-01h08m.01h27m         03h58m    (23h17m)0.07(23 52)
                                                 0.08(00 44),0.09
                                                 (01 12).
28-29     20 17 -20 48, 20 52 -21 21,            0.06(20 21),0.06
          21 24 -21 54, 22 04 -22 31,            (20 56),0.06(21 27),
          22 34 -23 02, 23 05 -23 42,            0.06(22 07),0.06
          23 52 -00 23.                 03 33    (22 36);0.06(23 07),
May-June                                         0.06(23 55).
31-1      20 07 -20 46, 21 20 -21 58,            0.06(20 11),0.06
          21 59 -22 30, 22 32 -22 59,            (21 24),0.07(22 01),
          23 10 -23 44, 23 46 -00 11,            0.06(22 36),0.06
          00 23 -01 16.                 04 07    (23 14),0.06(23 49),
June                                             0.08(0026).
2-3       21 39 -22 06, 22 09 -22 41,            0.05(21 43),0.07
          22 44 -23 28, 23 37 -00 10,            (22 16),0.06(22 51),
          00 14 -00 51, 01 09 -01 20.    03 07   0.07(23 42).0.07
                                                 (00 26),0.07(01 12).
                                     Total 23h44m=23.73h


Any iterruption of more than one minute has been noted. In the
fourth column of Table I the standard deviation of random noise
fluctuation sigma(mag)=2.5 log(I_0+sigma)/I_0 for different times (UT) of
the corresponding monitoring intervals is given.
    During the 23.73 hours of the monitoring time no flare was
observed.
Acknowledgement: The support of the National Hellenic Research
Foundation for this research is gratefully acknowledged.





          G. ASTERIADIS, F. MAHMOUD, L.N. MAVRIDIS
            Department of Geodetic Astronomy
               University of Thessaloniki