COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                    Number 2139

                                 Konkoly Observatory
                                 Budapest
                                 1982 May 7

                                 HU ISSN 0374-0676




             THE VARIABILITY OF BD+60d562




  This star was chosen as a comparison star for photoelectric observations
of LSI +61d303 together with two other stars, whose data are listed in Table I.


           Table I. Data about the observed stars


                 SP      V          B-V     U-B     Source
               ------------------------------------------------
BD+60d562(Var)         10.02var   +0.43   + .39   this paper
BD+60d493(A)   B 0.5Ia  8.44      +0.79   -0.30   Hiltner (1956)
BD+60d497(B)     O7     8.80      +0.57   -0.48   Hiltner (1956)


  The instrument used was the 60 cm telescope of Bologna Observatory
equipped with the three channel UBV photometer described by Piccioni (1972).




            Table II. UBV photometry of BD+60d562


                 Var - A                  Var - B         Adopted mean values
          ------------------------------------------------------------------
   JD-
2,440,000   V      B      U          V      B      U      V       B-V   U-B
----------------------------------------------------------------------------
4635.40     1.62   1.27   1.98       1.24   1.12   2.02   10.05   .45   .41
4638.38     1.62   1.27   1.97       1.24   1.10   1.99   10.05   .44   .40
4860.46     1.60   1.23   1.88       1.23   1.10   1.93   10.04   .43   .35
4863.43     1.57   1.21              1.22   1.08          10.01   .44
4865.38     1.51   1.12   1.79       1.14    .96   1.87    9.95   .39   .40



  In Table II we report the differences in magnitude corrected for 
differential extinction using mean seasonal coefficients, taking into account
also the colour effects of the atmosphere. The differences in magnitude
have been transformed to the UBV international system by equations obtained
from the photometry of some standard stars. On every night about 8 measurements 
were made; the standard error of the mean is of the order of 0.01m in
V and B, of 0.02m in U, but in addition systematic calibration error of
0.03m in V and B and 0.06m in U could be produced by the transformation to
UBV system.
  Nothing can be guessed about the type of variability of BD +60d562; since
its U-B index is positive, it is surely less reddened than the two comparison
stars and it has a later spectral type.





              C. BARTOLINI, P. CUSTODI
              F. DELL'ATTI, A. GUARNIERI
              A. PICCIONI

              Osservatorio Astronomico
              Bologna University - Italy





References:

Hiltner, W.A.: 1956, Astrophys. J. Suppl. II, 389 [BIBCODE 1956ApJS....2..389H ]
Piccioni, A.: 1972, Mem. Soc. Astr. It., 43, 159 [BIBCODE 1972MmSAI..43..159P ]