COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                        NUMBER 13

                                          Konkoly Observatory
                                          Budapest
                                          10 August 1962


                       V 536 CYGNI

     8 minima observed on plates taken by the 200/300/300 mm
Schmidt camera show that the period of V 536 Cyg given in GCVS 
(Moscow 1958) has to be halved. New elements have been derived from these
8 minima and Perova's 5 minima (Per. Zv. 7. 258,1950):

        Min, = J. D. 2428759.411+6d.01020. E
A=11m.8 - 14m.1 pg, D=0d.62, d=0d.06, The value of d is uncertain.

                                     P. AHNERT
                               Sonneberg Observatory

	


      REQUEST FOR PHOTOELECTRIC OBSERVATIONS OF AC AND

     This RR Lyrae-type variable shows considerable light-curve
variations. In 1958, 1960 and especially in 1961 we have obtained a
great number of photoelectric observations of the star at our 24 inch
reflecting telescope. These observations cast doubts upon the reality
of the two combining periods of 0d.525 and 0d.711 generally accepted up
to now. The true fundamental period of the variable is probably longer
than these ones. This is supported by the fact that according to 
Preston (ApJ 130, 507, 1959) the spectral characteristics of AC And are
similar to those of KP Cyg with a period of 0d.856.
     The problem of the star can be solved only by a wide-range
cooperation. Those who are ready to participate in this programme are
kindly requested to inform me about their willingness. I suggest as the
limiting dates of the cooperative observations September 20 and 
October 8, 1962.

                                       L. DETRE
                                 Konkoly Observatory
                                       Budapest