COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                          NUMBER 61
  
                                        Konkoly Observatory
                                        Budapest
                                        6 August 1964

                           Y CYGNI


      For the star Y Cygni exhibiting apsidal rotation R. S. Dugan
published in 1931 (Princ. Contr. No. 12) the following elements:

"Even" t_min = J.T. 240 9534.3195 + 2d.996 3331*n + 0d.1380*sin 0deg.06266*n
                                   - 0d.0074*sin 0deg.12532*n

"Odd" t_min = J.T. 240 9635.8175 + 2d.996 3331*n - 0d.1380*sin 0deg.06266*n
                                 - 0d.0074*sin 0deg.12532*n

     According to these elements the minima shall reach their extreme 
positions in 1967, the even minima passing through a negative,
the odd minima through a positive maximum.

      The correction of these apparently rather accurate elements
(s. A.N. 287, 186, 1963 = Mitt. Potsdam Nr. 106) will only be worth, after
a great number of exact moments will be obtained for the even and likewise 
for the odd minima in the next years, from 1964 to about 1970.

      Therefore I give in the Table below the moments of the minima
for the time interval 1964 August 12 - December 18 calculated by using
Dugan's elements. Only the first sinusoidal term was taken into account.
The minima given here are those for n = 9704 to n = 9750. In this interval 
the period will increase from 2d.996 277 to 2d996 284 for the
even minima and diminish from 2d.996 390 to 2d.996 382 for the odd
minima. Hereby, the odd minima will occur at the beginning of the 
interval mentioned 1d.754 and at the end of it 1d.759 later than the even
ones. A similar table for 1965 will be given later. The even minima
are not listed here since they occur in the afternoon hours.

     J. D. M. A. T. G.      U. T.

2438000.000+
    619.597      1964. Aug. 12d   2h.3
    622.593                  15   2.2
    625.589                  18   2.2
    628.586                  21   2.1
    631.582                  24   2.0
    634.578                  27   1.9
    637.574                  30   1.8
    640.571           Sept.   2   1.7
    643.567                   5   1.6
    646.563                   8   1.5
    649.560                  11   1.4
    652.556                  14   1.3
    655.552                  17   1.2
    658.548                  20   1.2
    661.545                  23   1.1
    664.541                  26   1.0
    667.537                  29   0.9
    670.534            Oct.   2   0.8
    673.530                   5   0.7
    676.526                   8   0.6
    679.522                  11   0.5
    682.519                  14   0.4
    685.515                  17   0.4
    688.511                  20   0.3
    691.507                  23   0.2
    694.504                  26   0.1
    697.500                  29   0.0
    700.496                  31  23.9
    703.492             Nov.  3  23.8
    706.489                   6  23.7
    709.485                   9  22.6
    712.481                  12  23.6
    715.478                  15  23.5
    718.474                  18  23.4
    721.470                  21  23.3
    724.467                  24  23.2
    727.463                  27  23.1
    730.459                  30  23.0
    733.455            Dec.   3  22.9
    736.452                   6  22.8
    739.448                   9  22.8
    742.444                  12  22.7
    745.440                  15  22.6
    748.437                  18  22.5

Astrophysikalisches Observatorium Potsdam, July 30, 1964.

                                             H. SCHNELLER